Ford P0171 P0174 P1101 - Ford Mass Airflow Sensor Diagnosis Video 

I have a 2002 ford f150xl and the layout was exactly the same. I appreciate your rundown and information so that I can perform the maintenance myself. I am hopeful that I will correct the issue and save myself a bill at the mechanic.

Just so people will know....always check the rubber grommet where the MAF wires plug thru the air intake tube thingie. If not sealed good, it will throw off all sorts of " this & that " probs and codes. This leak will also be missed during a smoke test. It is a large vacuum leak besides all the other common YT vids that repeat the same shtuff over & over. Also, they never tell you what a normal reading is for a sensor...

Thank you! Was having all kinds of intermittent issues with my ‘04 f-150 that I though were vacuum issues I just couldn’t find. I had replaced the MAS at one time, but it was a reman. I tried a new one at your advice, and it seems to be working, finally!

Great video. thx, your vids give me that little Xtra confidence to fix the things I can to save money, and the things that I can't and knowing the difference.

Tim, Another Great Video to rewatch. Plus side of that we get to see you smiling. Thx big guy.

Thank you . I enjoy your videos keep up the good work. You're doing a fantastic job.

Thank-you for taking the time to help us with troubleshooting ideas.

thank you for taking the time to show your knowledge and get us out of the hole

Knowledge is power. Thanks for sharing some wisdom with us!

I enjoy your videos keep up the good work. You're doing a fantastic job.

Always enjoy the videos particularly the Ford videos. I have a 98 with the 5.4 and the information is helpful.

This guy, Tim maybe, is just about the best at explaining this auto mechanical stuff that I've found on RU-vid. He has a good 'bedside manner' n seems to know his craft WELL as opposed to the many 'backyard mechanics' found on here whose experience n skills are a bit sketchy sometimes. Obviously Auto Mechanics is his profession. 1st vid of his I've watched but will definitely check out more. Thanks Brother.

Good morning. I'm just a DIY guy but I never turn down an opportunity to learn...or hang out in a shop. Thanks again, enjoy your day.

Wonderful articulated, thank you

Thanks for the descriptive video! A true professional at work! You've earned my subscribe!

your the man. i love my snap on computer. every mechanic needs one. gets right down to what u want to know. great video

My 96 Ford 4.9 had the same codes, P0171 and P0174. Cleaning the Maf sensor solved my problem.

You're a good, kind, patient, teacher. I have an F250 7.3 liter diesel powerstroke 1995, if you ever have videos for this make & model I'd be glad to watch those too. Good work you do & good job on the videos. I think you could teach anyone how to take care of their vehicles better - those of us who know so very little.

Exactly what is happening to me. I have 2008 Ford exploder sportrac v6. Already had the engine replaced. Thank you.

Hey There,,,,I have to say, that being a "girl" and having people like yourself out there with video's informing people like myself how to clean a MAF sensor was a HUGE deal!! I had to have my yearly emissions test the other month and did NOT pass, so I had put the codes in that had come up into google and found out what the "issue/s" were. Then went to RU-vid to find out how to attack this situation. Just to let you know, I cleaned my MAF sensor today and there is NO "check engine" light on, nor is there any RPM fluctuation. I can't thank you enough for posting this video and helping a "girl" with my problem!! HUGE kudo's to you!!

Great video and while not relevant for what I was looking for I still watched for possible future issues, I need to figure out how to wire my maf connector in my f150 so it will run correctly

Nicely done Tim and good tips all throughout!

mine (2008 ranger) has the same p0171 error bank 1 too lean, but so far everything I've tried hasn't changed the status. Engine runs perfectly fine. Changed out the air filter. Sprayed around for leaks didn't see/hear anything. Inspected hoses - nothing. Spray cleaned the MAS sensor. Ran a tank with fuel system cleaner. Still the same. Guessing O2 sensor. Sucks there's like four. Great job engineers. There really is no point to an error code when they're so broad it could be like 10 different things.

GOOD info and explanation as always thank you.

Thank You for such a thorough video! It was nice to watch an even paced, nicely toned, well narrated video. I believe and feel that it was very well thought out, presenting all the angles of the problem/issues upfront, variations of issues that are possible or encountered, and then the different ways to solve/fix the problem. Throughout watching your well made and presented video, the questions that I unexpectedly came up with .... BONUS: were magnificently answered (as if on cue). I am all prepared to meet with my mechanic tomorrow, now knowing all the necessary information I was looking for and needed! (It's always a PLUS when you are a female and walking into your mechanics with an issue w/your 4x4. Unfortunate BUT true) ~ Thank You, Thank You, Thank You - I look forward to watching your other videos! Would it be alright to set up links to your various videos for my fellow DIY Women Fix-It/Build-It Groups, Women SUV/Truck Campers, Women Hiking The Mtn Trails w/Their Dogs, Etc. ??? ~Amy

Thank you. Nice job

Thank you for your videos and time.

this video help me do work on my truck that would have cost me alot of money.so I owe you lunch or something.lol...thanks alot for your videos.so much help

Great explanation!

You're the man. Great vid.

Hey thanks for your videos.

AWESOME VIDEO MUCH THANKS

I have a 2005 ford f150 and it is doing the same thing in your video. Great video i learned alot

Thank you very much. Very much appreciated.

Good information, thank you.

Very helpful. Thanks!

Great video! But you made the process more difficult than it needed to be. I have a 2000 Ford F250 Super Duty with the 6.8L V-10, and my MAFS went bad. The light on the dash was on, and the truck started rough. I bought a new one and replaced it in a couple of minutes. I took off the band that holds the "nozzle" to the air filter box, took a screwdriver as you did and pulled out the unit, disconnected it, and replaced only the sensor with the small allen wrench that came with the new sensor. I did not have to replace the entire "box" that holds the sensor, and I did not have to remove the unit from the large unit that connects to the throttle body. It was much easier, with not as much disassembly. Keep up with the great videos! I do most of the work on my truck. 18 years old, 365,000 miles, and still runs great! Can't say that for the rockers, though. Cancer!

Perfect video

It's really helpful ,thanks a lot

Very helpful thankyou.

Thanks for the help/ I didn't realize my 2002 F250 maybe able to read fuel pressure on my scan tool. I bought a fuel pressure tester kit already. 😀😂

Awesome thanks for the info like!!!

I know this video is very old, but worth the shot. My check engine light has been on for months now. Issue I’m having now is that the truck cranks for a very long time before turning on. Sometimes when it does turn on it smells like gas and then will run like if it choked. I checked the fuel pump and they say it’s good cleaned out the injectors and changed the fuel filter.

Thanks doctor

Thank you sir.

I have p0171 bank 1. What do you think it could be, my Fusion is an 06 with 54,000. I just fixed the thermostate and then I got this code. Thank you.

This video was a big help for me - because I changed the air filter which was so very dirty - installed a brand new air filter - cleaned inside the throttle and the butterfly plate - then a check engine light came on ( WTF ) driving to Autozone they hooked up their machine and found codes : PO171 & PO174 - on their code sheet it reads the PCV valve is faulty - after watching this video of yours maybe the Map Sensor is dirty and needs to be cleaned due the very dirty air filter .

This guy is good!

Well done Tim 👍

Thanks for sharing

Thanks for all your videos!! One question. I’m getting a P0191, P0420 ,P0430, P2196,P2197,P2198 sometimes all together & sometimes just the p0191

I am surprised you did not attempt to first clean the MAF with CRC Mass Air Flow cleaner. Oftentimes that's all that's needed. To me it's like replacing the throttle body automatically without first just taking it off the motor, and spraying with Motorcraft throttle body cleaner and scrubbing it with a toothbrush to get the varnish and soot off it. So many times this is exactly what the dealer mechanics do. They don't bother cleaning anything' they just automatically just replace parts. That's why I do my own mechanics. Only thing I ever replaced on my Ford truck was a starter. Everything else is original, AND I have 324,000 miles on my '05 F150 with the 5.4 3V.

thanks it was right after the sensor. the mechanic who my mom took to get a tune up. they disconnected the vacume line. connected it back cleared the codes ran 200 miles no check engine.

Thank U great video I'm having the same problem on my 08 f-150 I pray that will fix it.

A very Smart guy...geez that engine is filthy.thx

Educational!!! Is there a reading the maf should be when motor warmed up? How many grams per?

Thank you

thank you sir...

Update. Started the van today and disconnected the maf harness clip while running amd stayed on. Drove local for about 5 miles to warm it up. All that showed on the obd reader was the maf codes because it was obviously disconnected. The p0303 and P0171 codes never came back on. Afer the 5 miles I reconnected the maf and drove hard for another 3 to for miles and ran completely fine with no check engine light. Any thoughts what could be the culprit? Maybe the coil pack is cracked and after so many miles of heating up it starts to misfire? Has brand new plugs and wires. Fuel filter clogged? Egr valve clogged with carbon build up? Sprayed brake cleaner along all vacuum lines and gaskets. No sounds i hear. Weird. Appreciate the feed back. 98 Windstar 3.8 limited 4 speed w/ OD

2003 3.0 ranger here.... you just described the problem. ( no power)

I'm having similar issues....what if the Mass Air sensor doesn't fix or change the problem in the video...i have a 4.2 thats having revving problems and shuts off sometimes ,a s well as popping and stalling....has a new throttle positioner sensor and fuel filter as well. Thanks for your help

thumbs up

Hi, thank you for the really helpful videos. They have helped me a lot. Quick question: I recently replaced my intake manifold + plugs, coils, injectors, thermostat w/ housing, water heater tube under the manifold, MAF sensor, CHT sensor, PCV pipe & valve & knock sensor (all Ford or Motorcraft parts). Before changing all that I had 4 codes - P0155, P0171, P1131 & P1151. The truck now runs great! BUT now I’m running 2 different rich codes - P1132 & P1152. You have any thoughts what could be causing these codes? Edit: I drive a 01 F150 V8 5.4 4x4 - 175k miles. It’s been a great truck. First time I’ve had issues.

I just bought a 2006 (the guy told me it was a 2008 when I bought it) Mercury Milan Premiere with a 3.0 V6 engine. When I bought it, the guy said it needed a cam sensor replaced. We did that, but now we are getting these codes and we are worried that we got a lemon. Is it possible these codes could indicate a timing chain needs to be replaced, or is it just a simple fix?

I have seen several videos that say if you unplug maf sensor it will stall out if you have a good sensor. Is it that easy??

P0102 MAF Sensor Circuit Low Input on 97 F-150, same difference? Getting a P0430 Catalyst System Efficiency Bank 2 Below Threshold also, figure I'll start by cleaning the MAF.

Hi, I just bought a 2006 Ford Escape XLT from an Auction. It was sitting for who knows how long and I have had extensive work done on the engine. It is now throwing a P0171 code. The shop has smoked tested it several times and found no leaks, replaced the intake manifold gaskets, done an snap test on the cat, and replaced the MAF. They are recommending I drive it for 200 miles and let the computer re-calibrate its self before doing anymore work since it has been setting for an undetermined amount of time. I seem to have bad mpg, it shutters while idling, and also seems to run fairly loud and rough. I feel that driving it for the 200 miles is a odd request, and wondering if I should get a second opinion or search for any other causes of this code.

So following this repair, did the check engine light go away immediately?

I have a 2005 Mazda Tribute 3.0 with 162000 miles. It runs great. The problem I'm having is that I get different miles per gallon for every tank full. On one tank full I will get 19 MPG, then the next I will get 15 MPG, then 13 MPG, Then 10 MPG, then 15 MPG, Then 19 MPG, and so on. Originally I used to get 20 miles per gallon. I have replaced the spark plugs, spark plug wires/coils, and every filter I can think of. I’m the type of driver that does not have a heavy foot. What is weird about this issue is that the gas mileage fluctuates so much. Could this sensor be the problem?

what if you get lean on one bank and rich on another bank. Runs well when started but has hard cold starts. Checked for vacuum leaks. also there is a rattle in the engine under load at low rpm almost like pre-ignition. No code specifically aimed at MAF. P0171 and P0175 and randomly had a p0300

hi, can you pliz help i have my c230 v6 2007 and it runs so smooth but it is showing the check engine light and i checked it and it gave me this code. i cleared the error but it comes out after a 5 to 10 kilometers of drive Self-adaptation of mixture formation for enrichment at partial load for the left cylinder bank is above the permissible limit. (P0174) permanet Self-adaptation of mixture formation for enrichment at partial load for the right cylinder bank is above the permissible limit. (P0171) permanent

If the MAF sensor is the problem will it always give both P0171 and P0174 codes. I'm just getting P0171 on a 2005 Ford E250. 5.4L 2 valve engine.

Would cleaning or replacing the MAS on my 06 f150 with a message reading “check gauges” help at all?

Hi I could not find air mass cleaner in my area so, can I use electronic cleaner? please help.

hey i have a 2004 f150 5.4 in it..and all i have to do is touch the plug to the MAF and the truck dies and it has codes p0011 and p0021 could that be related and why would it die when i touch

I have a zx2 it start and runs but I have to turn the fuel pump on twice to get it to start but if been driving it don't do this go new mass air and fuel rail pressure valve sencer and a new tune up but pvc valve and lines and many new parts but not iat and fuel pump but reading seams to be good

I've had all of the codes. more of the lean bank 1 codes. I've replaced all O2 sensors, new fuel pump, new fuel pressure sensor. new fuel pump module, new coil packs, new spark plugs, and today I've ordered the MAF, housing and all. I did take apart and cleaned with cleaner the maf, it's still shaking and idling rough. it's taking 1/4 to drive 55 miles. I know it's a V8, but that's alot of gas... I drive an 04 f150 stx, 4.6... Please help!!

im troubleshooting a 2004 f150 xl heritage 4.2l v6 with similar issues. was this truck a v6? im getting 3.7-3.8gm/sec at idle and 14.2 at 2500 held steady. similar iat etc as you showed. but 1600ft elevation.

Could the MAF sensor be bad even if you have no check engine light on? My truck was running fine (2002 F150 Screw 4.6) and I stopped to replaced my air filter. Could the possible jarring of putting in the new filter cause my MAF sensor to fail?My hot-wires looked clean but I also tried cleaning with CRC fluid and it didn't solve my problem. Any tips? +The Car Doctor

My girlfriend have a 2006 Kia Sorento and the code PO0016 showed up so do I just change the camshaft position sensor or do I change the ovs please help me

Thanks for the explanation, however I still have a question...how these MAF sensors go bad? My Mustang has this intermittent issue and there is no CEL but I do remember a couple of months ago the air filter (Spectre) it kind of "disassemble" itself and the car wanted to stall, after a couple of minutes I parked the car and check the engine just to find out that the air filter was unattached of the Cold Take pipes (So I guess I drove the car like that for a half mile). Can something like this accident can damage the MAF?

Hi, and excellent video! I have a 2002 F150 with the 5.4. I am chasing an intermittent P0171. I connected my scan tool and the STFT & LTFT go sky high. I've replaced the fuel filter, cleaned the MAF, replaced the DPFE and smoked the engine with no vacuum leaks. I have no drivability issues, but the intermittent code and the high fuel trims are bugging me. I always use Top Tier gas. Fuel trims at times at idle approach 25+ combined, and drop to around 15+ at engine speed and continue to drop at higher engine loads, like heavy acceleration. Any suggestions?

Do these tablets tell you what the vehicle's trim percentages and numbers are supposed to be?

98 windstar 3.8 giving p0171 and p0303. Can this be the issue for misfire?

To add I'm low on power now and it feels like an intermittent electrical issue.

Thanks for the video Car Doc. I have a 2003 4.2 that is throwing 171 and 174. Drives fine at all speeds, but sometimes the idle goes a little lumpy. Anybody have insight on that?

similar issues with my 1997 ranger 2.3 liter. It used to happen once a day, now every other stop sign, it happens. (1st or 2nd gear, let out the clutch, give it gaz, doesn't move, give it gaz, doesn't move, dies out. restart it and it goes... etc). no check engine codes, can it still be the MAF sensor?

What would cause a p0171/lean bank one, AND p0175/rich bank two?

I have a 05 with lean bank 2 rough idle and really rough sitting under load

Good day Mr.car doctor am having the same issue that you explain in the video,I also have another problem it's with starting my vehicle,I have a 2002 expedition 5.4,whenever I start the car it cranks but it doesn't turn on the 1st time,on the second try it stay on but starts a little rough but goes back to normal conditions can this be mass air flow issue.

Great video...why not just replace the Mass Air Flow sensor itself...without the plastic housing..i got a new sensor for $30 with out the black plastic housing?

Would it cause it to backfire or stumble or stall out

Thank you for sharing your video, I have a Ford 2001 E350 I replaced the Mass Air Flow Sensor, I get the code with the electrical problem. any tips to share ? I also get a humming noise when the Van is at stop coming from the air flow though I can't detect the cause. Any tips would help thnx.

Hey There...Well, I had to replace my Mass Airflow Sensor because the "Check Engine Light" kept coming up...I replaced it yesterday, and everything was running really well till today...I got the check engine light came on again, and the RPM's are going crazy, going up and down like mad...I have a code P0174 still keeps on coming up...so I am thinking that there is a LEAK in a hose???? Could I be right in assuing this? Thanks again

What is the life span of a MAF sensor?

I cleaned the maf sensor .It seemed to fix it then it threw I the 0174 code again.I cleaned the iac module. idle was going up to around 800 and dropping to arpund 500 and shutting off.2001 ford taurus with 213,000 miles

That's it no codes on my 07 F150 what the symptoms you described at the beginning of the video low power very poor gas mileage

Tim; the white f150 has a major dirt/grime issue under the hood, no wonder the mafs was wasted, air flow in that engine bay is sketchy at best. tell your customer its ok to wash your engine if you do it right. wow.

You know the harness that goes to that sensor on the outside how do I replace it

2001 F150 5.4L Engine L I have these two exact codes popped up as well as P0 304 and P0 308 (cylinder 4 and 8 misfire) When I accelerate in probably 3rd gear, the truck will erratically shake, but I can accelerate through that and if I keep it below 40 mph the truck will not shake. I have replaced the air filter as well as the fuel filter today. any ideas??? Thank you sir.