Toyota Po441, P0446 EVAP Vacuum Switching Valve VSV Testing and Canister Replacement 

Nice work. I like the testing with a 9V battery off the car, makes it easy and accessible to most people.

Polarity doesn't matter when you are energizing a solenoid. Just make sure the leads are not touching each other. We found a 9 volt battery does not work well for the vent solenoid, but you can use a power probe or the vehicle's 12 volt battery. Remember to do a tap tap tap test to find an intermittent solenoid which frequently happens. Mark Hicks Wells Vehicle Electronics

Yes, this is now confirmed. I cleaned up the hoses and put back. Then I did a drive cycle (cold engine, took out gas cap and tightened, warmed up for 3-5 minutes, 10+ seconds with high idle speed, then idled the Sienna with AC on for 35 minutes). The evap is now "ready". This feels so good since I almost wanted to surrender this weekend. Thanks Mark for being be my mentor going through the process. Many many and many thanks!

It sounds like you are doing everything right. Be sure to check the hoses very carefully. Next to the VSV cracked hoses are the most common problem. Thanks for staying in touch. Mark Hicks Wells Vehicle Electronics

@sidmalicious : 2. Monitor the FTP sensor and unplug the 3-way VSV and draw a vacuum into the canister and verify that it will hold vacuum and the FTP voltage will decrease. 3. Test and verify that the purge solenoid and wire harness are all OK. The purge solenoid should apply vacuum to the charcoal canister when grounded. Also verify that the hose from the purge solenoid to the charcoal canister does not leak. Hope this helps you, Mark Hicks Wells Vehicle Electronics

Good afternoon! I have noticed that you are still responding to some comments so I figured I could give it a try and ask! I have a 2002 Toyota Camry LE 2.4L. I was receiving CEL code P0440. I went to a shop, they performed a smoke test, and they replaced my "intake control vent solenoid valve". CEL came back a about 2 days later with now P0440 and P0441. So I then replaced my gas cap with an OEM Toyota fuel cap and I reset the codes. Another 2 days later, the same P0440 and P0441 codes came up. I then replaced the VSV, VSV Assy no.1 along with all their hoses and deleted the codes. Again, the same codes came back 2 days later. At this point, I decided I had to replace my vapor canister since I had already replaced everything else. Well... it was tough but I managed to install a brand new charcoal canister over the weekend. Once finished, I erased the codes and felt confident it would get rid of the evap CEL codes. Then... my CEL came on today (again, about 2 days since the replacement) 😵 but now I have codes P0440, P0441 and now P0446 as well 😞 All of my hoses are fine and every single part I replaced with brand new OEM parts. Is there something else I have to do in order for these pesky codes to go away? Do I have to reset my ECU? How would I do that? Are these just the old stored codes that weren't deleted when I "erased"/reset the CEL codes? My OBD II device says that "some codes that are stored cannot be erased" when I cleared the CEL. It is a device I bought from Walmart. Do I need a more advanced machine in order to fully reset the codes? Do I just need to keep driving it to 100 start-ups? (I've only started it around 10 times since I replaced the canister whwn the CEL came back) I just want these dang codes to go away and for my car to function properly again. Please help!!! 🙏

Thanks for taking the time to leave the very nice comment. It means a lot to us! Take Care, Mark Hicks Wells Vehicle Electronics

@h23sirlude It is our pleasure! Thank you for viewing it. I wish you and yours a very Merry Christmas and a prosperous New Year. Mark Hicks Wells Vehicle Electronics

I apologize and completely agree. If the VSV checked out to be functioning, the nest step is to smoke the system. You are also right the majority of techs just want to replace a part without testing. I feel this is the case for a couple reasons. 1. shops that only want to pay the techs for time spent for R&R and are just interested in getting the next vehicle in the shop. 2. The shop owners and service writers that have not educated their customers that the best way to repair is to diagnose

Thanks Mark. The drive cycle was helpful. For evap, the drive cycle is primarily to idle (after with high idle for 10 seconds) with AC on for 20-50 minutes. I also found that with a new gas cap was not the solution since P0446 etc came up again. But, I have a BIG finding just now. I just took out the 3 hoses (white, red, blue marked). The blue hose was blocked completely by something. So, I am so excited to post you the current status now. I think the blue-marked hose is the problem. Cheers!

At the time we did the video no one did not sell them separate. But i am glad you brought it up, now we and others do offer the VSV both ways. In fact we brought it up to our engineering when we finished the video. Seemed like a waste to us. Mark Hicks Wells Vehicle Electronics

@chapshow1 The EGR and EVAP are two separate systems. If you have problems with the EGR valve there is no reason to think you will have problems with the VSV. If you have any other concerns please let me know, Mark Hicks Wells Vehicle Electronics

Mike I just checked and Dorman does have a replacement for the vehicle in the video. Way to go Dorman! To the best of my knowledge this was not available 3 years ago. Thanks again for bringing it to my and all the viewers attention! Mark Hicks Wells Vehicle Electronics

Thank you for this video. I just brought my car in to the dealer because the "check engine" light turned on. The dealer told me in brief what the problem was, but I'm thankful for this video which has given me a much better understanding. Thank you Mark.

I agree, wait to see if the code(s) set again. If the PCM does not detect the issue in 50 starts it will clear the pending code. Stay in touch! Mark Hicks Wells Vehicle Electronics

@Standingwithfeast Thank you for the kind words. Problem is you have to have two of them. That might be an issue for some shops. Testing the VSV activation with a battery will reveal most of the failures. Mark Hicks Wells Manufacturing L.P.

The vehicle in the video had the early design. There was no way to replace the VSV alone when this video was produced. It is entirely possible Dorman have developed a replacement I am unfamiliar with. The bulletin we show in the video is right from Toyota. Just a thought you may have a late 1999 vehicle with the new design. If Dorman has come up with a replacement it is great news. However, to be sure it is a VSV issue the diagnostics in the video will still work. Thanks for the comment Mark

@JUDGERAMBO If you are asking about this Toyota, you will need a scan tool to read the pressure then verify that the 3-way Vacuum Switching Valve (VSV) by the canister works correctly. When the 3-way VSV is grounded, the pressure sensor should read tank pressure. When the ground is taken away from the 3-way VSV, it should switch and allow the pressure sensor to check for vacuum in the canister. I hope this answers your question, Mark Hicks

In the video description and in the video it explains this is an early version. In the early versions, the VSV and canister were one. You could not replace the separately. It also explains in the video how to determine which model your vehicle has. Mark Hicks Wells Vehicle Electronics

Voltage is supposed to change at approximately 1" Hg vacuum. Try testing this switch several times to see if the switch is sticking. Replace the NVLD if the switch is sticking. It is very common for the NVLD to fail on your vehicle! Stay in touch, Mark Hicks Wells Vehicle Electronics

I have no mechanical skills but I must say your video was very helpful on letting me know what needs to do.

@ikinner Thank you for the kind words. It is our goal to accomplish just what you said, a better compliment could not be made. Mark Hicks Wells Vehicle Electronics

It is somewhat common for a poor ground on the MAF sensor to cause this issue. Backprobe and check the Mass Air Flow Sensor ground on the Light Green wire - look for 0.03 volts or less to be ok. If I were you I would take it back to the dealership and make sure they perform this test. I would also demand to know which codes set. It is your vehicle, my friend, you have every right to know! Stay in touch please, Mark Hicks Wells Vehicle Electronics

If you have already replaced the VSV with the same results, we will have to assume at this point it was not the issue. Again it recommended to replace both the charcoal canister and the VSV as a unit. I am surprised they did not recommend it. Mark Hicks Wells Vehicle Electronics

It is common for the 3-way VSV to stick or not operate correctly or for the charcoal canister to be faulty. The charcoal canister has valves built inside, so always replace the canister and 3-way VSV as an assembly, so the code does not reset. Mark Hicks Wells Vehicle Electronics

@Motocrossx23 If you do not hear any clicking the solenoid is defective. If you can purchase the VSV separately than you can replace it. I dont think you can, but let me know how you make out on this one. Mark Hicks

Test and verify that the purge solenoid and wire harness are all OK. The purge solenoid should apply vacuum to the charcoal canister when grounded. Also verify that the hose from the purge solenoid to the charcoal canister does not leak. If the vacuum switch is replaced, clean the inside of the vacuum switch with brake cleaner. Spray brake cleaner into the ports on the new vacuum switching valves to clean the inside.

@dmorley100 Yep still kicking. Problem is sleep keeps getting in the way of making more videos! Glad you liked it!

@xx217xx It means the solenoid is activating, but you still must make sure it holds and passes vacuum like it shows in the video. By far the most common cause for these codes on your vehicle are either a bad gas cap or canister. Here are some more instructions I hope will help you determine the anser to the problem: 1. Verify that the Vacuum Switching Valve (VSV) for the pressure sensor (located on the canister) operates correctly.

At the Natural Vacuum Leak Detection (NVLD) assembly, which is mounted near the fuel tank, backprobe the Violet/White wire with a voltmeter. Locate the vacuum line going to the canister and remove the line so a hand vacuum pump can be used to put vacuum on the line going towards the NVLD. The other line at the NVLD goes to the vent. Block the vent line. Using a hand vacuum pump, apply vacuum to the line while watching the voltage on the Violet/White wire.

Thanks for responding Mark... as it turns out my problem was the gas cap. A trusted mechanic cleared the error codes and the problem has been resolved.

@markjhicks 3. If both solenoids operate correctly and are not sticking, inspect for a restriction in the Evaporative Emission (EVAP) lines that could affect how the canister vents after a leak test is performed. 4. Verify that the fuel cap is a good seal. If the fuel cap leaks or does not hold the correct amount of vacuum when the system checks for a leak, all the codes will set. Stay in touch Mark Hicks Wells Vehicle Electronics

1. Verify that the Vacuum Switching Valve (VSV) for the pressure sensor (located on the canister) operates correctly. This is a normally closed (N.C.) valve. When energized, it should open. When de-energized, an internal spring should close the valve. 2. Verify that the canister closed valve (located on the air filter housing) closes and does not stick closed when operated. This is a normally open (N.O.) valve. When it is grounded, it closes and it should never stick closed.

Agreed. Thanks for the comment! Mark Hicks Wells Vehicle Electronics

@sidmalicious Chances are you will need to replace the charcoal canister with the VSV valve. But here is the test procedure if you would like to test it first: : 1. Verify that the 3-way Vacuum Switching Valve (VSV) on the canister operates correctly. When the VSV is not grounded, the Fuel Tank Pressure (FTP) sensor should be connected to the canister side of the system only. When the VSV is grounded, the FTP sensor should monitor only the fuel tank. Read first Mark Hicks Wells

3. If both solenoids operate correctly and are not sticking, inspect for a restriction in the Evaporative Emission (EVAP) lines that could affect how the canister vents after a leak test is performed. 4. Verify that the fuel cap is a factory part. If the fuel cap leaks or does not hold the correct amount of vacuum when the system checks for a leak, all the codes will set. Mark Hicks Wells Vehicle Electronics

I have a '00 camry CE. it WAS the canister. Thanks for the info guys. 👍. I invested in a smoke test after replacing gas cap and vsv by canister and actually found out the top part of my canister was cracked. 😂. I shook it and it sounded like a rattle. Even my rough and crazy idling got fixed.

Nice find! We focus on diagnosing to find the failure. On this particular vehicle, we started with the VSV and canister because they are so common. If they would have tested good, we would have went further and smoked it. Thanks for your input and keep up the great work. Mark Hicks Wells Vehicle Electronics

Nice video I got an 2.2l camry 98 with 359,609 miles still going strong and running has a rear main seal leak but it doesn't leak now I put a heavier weight oil and do a oil change went for an inspection today and it passed easily if the motor goes out probably replace it or get an bmw nice video sometimes these cars are hard to pass inspection

1. Verify the Black wire pin 2 at the Idle Air Control (IAC) has battery voltage. Check the wires from the IAC to the Powertrain Control Module (PCM). 2. Disconnect the PCM and the IAC, apply 12 volt power with a fused jumper wire to each wire one at a time. At the other end of the harness use a high beam headlight for a test light, the light should be bright at each wire that power is applied to.

@xx217xx Yes, it can happen and it is not unusual with an EVAP code. However, the code is still stored in the history even if the light goes out. Mark Hicks Wells Vehicle Electronics

It is very common for the Evaporative Emission (EVAP) Pressure Sensor Purge Vacuum Solenoid Valve (VSV), located next to the canister to cause this code. Have the technician activate it, to see if it is sticking. IF the hoses connecting to the canister have charcoal in them, the canister will need to be replaced. If not it is probably OK. Mark Hicks Wells Vehicle Electronics

@CRISTIAN123JOSE You can smoke it, but it will not show if the VSV is activating. You can activate it with a 9 volt battery without removing it. This is what usually happens when they fail. Mark Hicks Wells Manufacturing L.P.

Many times a lite click is an indication of a defective valve. The only way to be sure it is functioning properly is to also apply vacuum to it as in the video. I hope this helps, please let me know what you find, Mark Hicks Wells Vehicle Electronics

You replaced the right part. If the check engine light comes back on let me know. Getting the monitor to reset can be a real challenge sometimes. I suggest just driving it, it will eventually test and reset. Unless you are going in for an emissions test. In that case I will send you the drive cycle information. Mark Hicks Wells Vehicle Electronics

If you are talking about the EVAP code, no it will not make your engine shake. Be sure to check the tune up. Do you have any other codes? Mark Hicks Wells Vehicle Electronics

Check fuel pressure while the problem is occurring. I would also look at spark at the same time. If the spark cuts out and then the engine dies you know you have a spark issue. The next step is to determine what system the problem is in. If the FP is good and spark never cuts out but the engine died, then you need to look at injectors, to make sure they are firing at the point of dieing. Mark Hicks Wells Vehicle Electronics

UPDATE: No parts stores list the VSV valve separately, but after hours of research, I found the part number of the VSV valve for my '99 Corolla. It is 90080-91240. It costs about $27 from internet dealers or $48 from local dealers.I disassembled the old valve, and it looks good, so I don't understand why it doesn't switch like it should. Even the resistance of 40 ohms is the same as the new valve, but it doesn't switch or click. I have a couple of other problems with my car, so wont be able...

2001 Toyota Avalon. 3.0 V6 with VVti. I've already replaced the VSV that is on the air filter box 6 months ago. Thanks and I really appreciate your help. I've also replaced the gas cap when the dealership replaced the charcoal canister.

@mcleod2 The purge solenoid, I would think is the same as the purge valve. However, some manufacturers call out different names. I would check with whoever you are buying the part from to be sure. Mark Hicks Wells Vehicle Electronics

It is very common for the Vacuum Switching Valve and charcoal canister to cause a P0446 code on a 99 Lexus es300. But without testing it is no more than a guess. Mark Hicks Wells Vehicle Electronics

What code are you setting? Mark Hicks Wells Vehicle Electronics

It was a history code. If the code does not set again with in 50 engine starts it will erase. at some point you must have set it. If you have any other questions let me know. Mark Hicks Wells Vehicle Electronics

Verify the gas cap is the correct application and that it performs up to OEM specifications. Mark Hicks Wells Vehicle Electronics

The swoosh you hear is usually because the vent valve or solenoid is stuck closed. A P0446 on your vehicle is usually a defective VSV or canister. Here is the test procedure ... Please let me know how it turns out: 1. Verify that the 3-way Vacuum Switching Valve (VSV) on the canister operates correctly. When the VSV is not grounded, the Fuel Tank Pressure (FTP) sensor should be connected to the canister side of the system only.

@markjhicks This is a normally closed (N.C.) valve. When energized, it should open. When de-energized, an internal spring should close the valve. 2. Verify that the canister closed valve (located on the air filter housing) closes and does not stick closed when operated. This is a normally open (N.O.) valve. When it is grounded, it closes, and it should never stick closed.

@lanzce80 I wish i had a direct answer for you...here is what i know. I have not changed one on 2007. I looked it up in AllData and in the location chart it shows the canister in the same area, under the trunk - near fuel tank. But the picture is not specific. I think it is easier than the one in the video, because the labor rate for replacement was only .5 hours. Please take a look in that area and let me know what you find. Thank you and may you and yours have a wonderful holiday. Mark Hicks

@2009jimmy2009 How many customers are happy when they get the bill? But you are right this is an expensive repair. It is a questionable design from the beginning. If the VSV was made to be replaced as a separate component the cost would drop dramatically. Thanks for the comment. Mark Hicks Wells Vehicle Electronics

3. If any wire does not illuminate the light or is dim, trace or replace that wire and retest the operation. It is common for the black wire back to the PCM to have an issue. Mark Hicks Wells Vehicle Electronics

@sidmalicious I am a little lost, I help many people everyday, I am sorry I don't remember every vehicle. What is the year, make, model and engine size. Also what code(s) are being set? Mark Hicks Wells Vehicle Electronics

I have a 2001 Sienna with the late style vsv. While testing the vsv, I heard a small click, but nowhere near as loud as the one on the video. Is that still considered ok? All connections and the charcoal canister look ok (no rust). No heavy oder of gas anywhere including the hoses. Don't want to spend money on canister unless I have to. Any help will do. Thanks

great video, very in depth im not knowledgable on the evaps on toyotas but i got a car with this problem got it done real fast

Clean the airflow meter and retest drive the vehicle. Add a supplemental fuel supply when the problem is happening. Check to see if the engine runs better. Check fuel pressure. Let me know, Mark Hicks Wells Vehicle Electronics

I have the same trouble code P0446 on toyota camry LE V6 could it be the charcoal canister on mines?

Awesome video thank you Plus learning that a 9V Battery can actuate the valve enough to see if it’s faulty or not is fantastic

Usually, these codes on your vehicle mean either a vacuum hose leak or a canister that needs replacement. As far as the misfire, check the timing marks, it is common for the water pump to begin leaking and cause the belt to slip. Could they be related? I have no history to say yes, but is it possible? Yes, I guess it could be. First check for vacuum leaks and then the timing belt. Mark Hicks Wells Vehicle Electronics

Usually I personally do all the diagnosis myself and then I take the vehicle in for the shop to do exactly what I want him to do. Over the years, he has realized that I know more about my cars than he does. In this particular case, I was lazy and I knew up front that this was going to be a nightmare from doing all the research over the internet. So when the shop said, they have replaced bunch of VSV to fix this problem, I went for it. I do take some responsibility for this.

My 99 toyota celica gt, 5sfe engine, has no running issues at all. This video is basically the same as what I'm dealing with. I changed my canister with a used one I happened to get from pick n pull some years ago, my friend and I used a 9 volt battery to check the valve, and it worked, the valve is dead on the one that was on the car, I thought we had fixed the problem, but I still have p0446 cel. I've also replaced the vsv for the vapor pressure sensor, still cel, I've also replaced the gas cap, still cel. I don't think I have a vacuum/pressure leak in the gas tank/filler neck because when I run my car to E on the gas gauge, there is suction when I take the gas cap off....so that leaves vacuum lines or the ecu. Last time I had a mind F cel, it was for the egr, I replaced the entire system,...it was the ecu. I got a used ecu, cel gone. I think I'm gonna try the ecu next. Any help is appreciated!

@CoolasIce2 Unfortunately the VSV is integral to the canister. Not a very thoughtful design when it comes to replacement. But, there have been improvements to the original design and hopefully you will have to do this replacement only once. I wish I had better news for you, $250 is a lot of money to me too. Mark Hicks Wells Manufacturing L.P.

What do you mean? We tested the VSV and it failed, so it was replaced. How is this not diagnosing? We would have included the test in the video even if it would have tested good. We then would have taken it further and smoked the system. Mark Hicks Wells Vehicle Electronics

I want to apologize for the slow response, medical issues. An EVAP problem will normally not stop the vehicle from running. Make sure the fuel pressure and spark good while the engine dies. We first need to find the the problem system. Mark Hicks Wells Vehicle Electronics

I'll take the lack of swoosh as a good thing. Used vacuum pump to confirm both VSVs are working when properly powered - they're ok. I didn't make it to step 2 before I noticed the vapor pressure sensor was plugged into the wrong port on the 3-way VSV on the canister. I rerouted it and confirmed the others according to the underhood diagram. I hope that takes care of it. Will take a couple of drive cycles to clear the pending status. Will update when I know more.

I will assume you have the 6 cylinder. Most common cause are the vacuum lines near the air cleaner. Next most common is the CCV or canister close valve. Stay in touch, Mark Hicks Wells Vehicle Electronics

Great question, the answer is no. I am going to assume you are talking about the vacuum switching valve. If it were "on" or stuck in the closed position the computer would detect the problem through an evap monitor test. It would realize there was a problem somewhere in the evap system because the pressures would not be correct. Remember, there is no code that says replace this part or any part! The computer can only point you in a direction. Mark Hicks Wells Vehicle Electronics

@jimmyismealright Thank you for posting your experience. It was our pleasure to help you. Mark Hicks Wells Vehicle Electronics

What year, Make, Model and engine size? Mark Hicks Wells Vehicle Electronics

Perfect! Everybody loves an easy fix! Thank you for sharing the results with everyone, it is much appreciated. Mark Hicks Wells Vehicle Electronics

Perfect! Thanks for letting me know! Take Care, Mark Hicks Wells Vehicle Electronics

@<a href="#" class="seekto" data-time="186">3:06</a> you said that the vsv was deffective and that you needed to change the evap canister but i looked it up and they sell the vsv seperate what is your 2 cents on that matter

You should be able to just replace the VSV. Stay in touch, Mark Hicks Wells Vehicle Electronics

@sidmalicious By sputtering, I will assume you are saying it is misfiring on acceleration. Your vehicle does have problems with injectors. But, be sure the ignition system is in good shape. Quick test for the injectors: if you can power brake and recreate the problem, have someone do that and you stand on the side of the vehicle ( not to get run over) then spray crab cleaner in the air intake and see if the problem goes away. If it does you have a fuel related problem. Mark Hicks Wells

Thanks. I thought my tag will expired next month December, but just noticed that it is November (need an emission test). I have replaced the gas cap 2 days ago, and checked the hoses. I should be able drive another 150 miles in this week. I think I should go to do the emission test in 10 days, and if it fails then I would need to ask an authorized emission specialist to work on it (with $150 or more repairment to get a waiver if failed), to avoid an expired tag ticket. Hope the gas cap works.

Hey guys.. Interesting video.. I know it was posted almost a couple years ago now, but I am curious why at the time you didn't smoke test the system to check for leaks? As you mentioned in your video the code could be set by a leak.. I recently had a 98 come threw my bay at work setting a P0446 code and failing emissions cause of it.. It had been back and forth to the dealer for the same code 8 times over 2 years trying to solve the problem.

To be honest I don't exactly remember, I think I squeezed them. Mark Hicks Wells Vehicle Electronics

The EVAP system has nothing to do with how the transmission is shifting. I think you said you had the transmission replaced. I would suggest going there to have them look it over. Before i can say anything about the canister replacement, I need to know what code was set. Mark Hicks Wells Vehicle Electronics

@EricTheCarGuy Hey Eric, Thank you for the kind words. In fact a 9 volt battery can be used to do all kinds of testing. I know it is a secret, but I cant wait to see your new video!! Mark Hicks Wells Manufacturing L.P.

first and then replace. But to make this efficient the tech needs to be educated, not only in tools but system function. If a tech understands how a system functions, the wide majority of the time he will be able to diagnose it in a short amount of time. Mark Hicks Wells Vehicle Electronics

I would assume it is correct. But you can call the parts department and ask them. I would just to be sure. Mark Hicks Wells Vehicle Electronics

Have you checked the gas cap? If the cap is OK chances are you will need to replace the canister. Let me know, Mark Hicks Wells Vehicle Electronics

If you have a 1997 4 cyl, it is located by the sir cleaner. Mark Hicks Wells Vehicle Electronics

The canister is common issue on your vehicle. I know they are expensive but without smoking the system, it is my next best guess. Mark Hicks Wells Vehicle Electronics

Hi, thanks again for your help. After the replacement of VSV in August (shown in October that did not work), I replaced a new evap charcoal canister 3 weeks ago (early November). This time, P0440, P0441 and P0446 were pending after driving 100 miles, then P0446 was checked today after driving an additional 300 miles. I have just replaced a new gas cap now, and hope it would work. I would also look more closely if all hoses are OK. Please let me know if you have any further comments. Thank you!

We are talking about your reply to the person (crazycanadian05) who had this code multiple times and the shop and dealer and replaced bunch of parts until smoke test found the leaking hose. You will agree that smoke test should have been done before replacing the expensive canister. At least VSV is under $100 and if it does not click, would be obvious candidate to replace. But many mechanics, including mine, replaced it without doing any diagnosis on it.

Just wanted to add that sometimes because the solenoid clicks doesn't mean its 100% good. You should follow it up with testing it with a vacuum pump. Cas ein point on my Camry the solenoid at the air filter was clicking but it wouldnt hold vacuum. It's a normally open valve and when voltage is applied its supposed to close. Mine let vacuum acummulate but would bleed off slowly. This is what was causing my issues.

What is the number of the code? Mark Hicks Wells Vehicle Electronics

As long as all the hoses are OK, the canister would be next. Let me know what happens. Mark Hicks Wells Vehicle Electronics

The canister had been replaced with along with the updated 3 way VSV and a new pressure sensor.. When I got the vehicle I wasn't sure where the vent was so I smoke tested the system to find the vet... When I did find it I blocked it off and found the plastic line between the canister and fuel tank had rubbed threw behind the clip that held it in place.. A new hose seems to have solved the problem..

2. Monitor the FTP sensor and unplug the 3-way VSV and draw a vacuum into the canister and verify that it will hold vacuum and the FTP voltage will decrease. 3. Test and verify that the Purge Solenoid (PS) and wire harness are all OK. The PS should apply vacuum to the charcoal canister when grounded. Also verify that the hose from the PS to the charcoal canister does not leak. Mark Hicks Wells Vehicle Electronics

You should be able to get the VSV separately. Mark Hicks Wells Vehicle Electronics

Hi, Best video I've found. I got a P0446 code on a 1999 Toyota Avalon. I removed the canister and tested the VSV by following a Chiltons manual. I thought it failed the Ohms test so I replaced it. I tested the new VSV following your video. After applying vacuum to the VSV Pressure Sensor and Purge valve hoses it held vacuum when the solenoid was activated then deactivated but when activated again the vacuum on the purge side didn't go to zero, it went to about 8. Thinking I may have gotten a defective part I tested the Ohms and it was within specs. I then realized that the original VSV was checked using the wrong specs so I I rechecked it and it also was actually in specs so I reinstalled it to the canister and did the vacuum test. This VSV also did not return to zero. I hung at around 5. I'm now wondering if this means I have a bad canister and/or if there is another test to isolate the canister. Please advise. Thanks.