Chevy / GMC Truck - Running Lean P0171 & P0174 

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I love that we live in a world where this info is free and you can make a good living giving it to us, I learn so much

21:38 -- "It's only "temporary" unless it works." That law applies to every "temporary" repair that's ever been made.

This is scary. When you saw the disconnected outflow tube and pointed out the aftermarket intake, I thought...half joking to myself...."drill a hole in that puppy and put the hose there...." And that's what you did!! I'm a computer nerd learning auto repair. Awesome. Thanks so much for these videos, Eric!

I've listened to a lot of Techs on this sight, but none as smart as this guy. He not only talks a good show .... but he backs it up with substance. Thanks Mr. Obrochta for sharing this video .

Mr Eric O., I'm in my 60s and wish I had someone like you near me to repair my vehicles. I enjoy your channel very much thanks for sharing all your knowledge. you're a class act.

two quick tip tuesday..... #1 MAF numbers close to to size of engine .....#2 dont erase codes after fix with fuel trim in mind .... great tips

I always learn from your videos, you are one hell of a diagnostician.

My favorite local automotive machine shop has a huge sign saying "Stock is Not a Dirty Word". I agree completely. My ten year old truck is still completely stock and runs as designed...... I intentionally avoid aftermarket stuff. As far as the PCV tube is concerned, I would have tried to source a rubber grommet that fit the elbow and drilled the intake to match the OD. OEM uses this arrangement frequently. Thanks for another great video!

I have a 2004 Suburban here with a Spectre cold air intake with pending lean codes .Customer dropped it off with 204,000 miles and has only owned it for one week . Your video was great and I appreciate all your hard work in helping other auto repair mechanics become better at what they do.Thumbs up

As always, great approach. The folks in that area are lucky to have your skills to call on. Thanks for the video.

I found this interesting.... good direction from the door. You handled it flawlessly, minus the hiccup with the adhesive. Never cease to amaze me Eric!

I accidentally pinched the #6 fuel injector line on a spider fuel injector assembly when I replaced the assembly and saw positive fuel trims from a 2001 Silverado at over a positive 42 which at the time I thought they would only max out at 25. Of course I had the number 6 associated misfire code as well. I literally had to use ties to ties back the rear injector lines because they were slightly longer than the stock assembly. Lesson learned. The maxed out lean code was due to a lack of fuel to a single cylinder on bank 2. I am learning alot from Eric and I appreciate his commitment to the Auto Repair Community.

You are a true professional! I’m glad people like you make videos that actually helps people ! Thank you for your lecture

"Smoking like a freight train".. Been many years ago I heard that one. Best channel to hear all the old sayings.

I used to have quite a collection of "Cold air intakes" i removed to fix customer's problems. Thanks Eric!

Thankyou so much for the explanation at the end which summarizes the "why" factor. Learning how these systems work and the thinking process to come to your determination is highly valued by myself. Cheers Doug

You sir, are a pro. I wish I had a tech like you in my area. We're stuck with part changers over here.

You are funny Eric! I love the the line “The MONEY LIGHT is on.” Not too many would appreciate it, I think it’s absolutely hilarious! You are not wrong. You’re videos are informative but as I hope everyone realizes that every situation is different by design. Geography, driving conditions, drivers mood at the time driving the vehicle at all times, and the the DIYers ability to use your tools. It’s obvious that your knowledge comes from years of experience, however the tools is something you’ve built up over all those years. Technology has changed the combustion motor as I knew it growing up born in 1966. Most of the videos I have seen from SMA utilizes all of these great tools you have to diagnose, which almost always winds up not being something I can diagnose myself. I’d like to have your tools but that is not happening in my lifetime. I am forced to to take it to someone with the tools you may or may not use, but one thing is for sure. I go in with knowledge that I didn’t have before watching you do what you do so very well. Whether or not it helps me when dealing with a professional wrench turner or in fact makes it worse because I’m suggesting things to him that he really doesn’t want to hear. I don’t know for sure, but I do know that I’m not paying for parts and labor on stuff that I know the vehicle did not need. The mechanic who just throws parts at a vehicle to see if it fixes the problem should have his ability to do repairs on vehicles for money revoked permanently. Geography plays a role for the obvious reasons. With you in New York and me in Southern California, the stuff you spend time on like removing almost all under carriage components that are rust engulfed, takes me no time at all because that’s not an issue here in my region. Driver mood is important because you either have a car that was driven all its life by a little old lady who went to doctors appoints and bingo less than 7miles from her home and never going over 40mph, or a younger to middle age person who has to be in lead foot mode all the time who has driven all over hell and back. If I’m buying a used car I prefer the former rather than the latter. I’m enjoying your videos and it is informative whether I do the repairs or not. Thanks, it’s much appreciated!

That's gotta make you feel good, diagnosing an issue that another shop couldn't figure out. Thanks for taking us along!

I use grommets when doing conversions like this. Your work is spot on thank you for your time.

Excellent repair! It amazes me that so much work comes from other shops.

My favorite video so far. Excellent explanation of fuel trims

In the Star Trek universe you'd be Montgomery O. Kirk pushes the button on his chair..."Mr. O, how long before we have warp engines back on line ?" "I'm sorry captain, it says 24 hour cure on the box." :o)

SWEEET 👍 👍, high temp red silicone... Stuff sticks to anything. And its nice and bright. Lets people know you've been,there 👍

Classic! "It's only temporary unless it works." Sooooo true!

I am no mechanic, but enjoy learning and doing my own repairs on my '08. I have almost the identical problem with mine. And a huge thanks to your explanation of what all was happening with the lean fuel trim code, I know mine is a vacuum leak as well. Thanks so much!!

Great job eric , nice when the dealership brings the easy ones to you . Makes me nervous this shop could not handle it ! The power of visual observation. The brain is a great tool to employee when others can not figure it out ! Proves the rule of life : "You can never just do one thing".

Modern two part epoxies, millions of uses. Flawless diagnosis... Great job Eric!!

"It's only temporary, unless it works." I'm stealing that!

This goes to show how integrated seemingly simple things are on newer vehicles. A Vacuum leak at an improperly installed quick disconnect fitting, and an air source to the engine PCV System not feeding from the MAF, for "unaccountable air". Brilliant diagnosis. By the looks of the dirt on that 3/8" hose, it has been that way for a while. I was a bit surprised to see how quickly and predictably it corrected and re-learned the new values..... REALLY good lesson in Fuel Trims. The ONLY suggestion, I would have drilled out the hole a little larger with a step bit and installed a plastic or rubber gromet, then a little rubber grease and push in the elbow. That way it will self align and not be prone to cracking. That can still be done if there is a problem in the future. GOOD FIX. I too shudder at the suggestion of "Cold Air Intake" and other aftermarket junk that people spend good money on... only to create problems. The OEM's spend a lot of time and money to design things like induction systems that are functional, quiet, dependable, and as efficient as they can be for the overall vehicle. The "Gains" to be made from aftermarket systems are quite often narrowly focused and marginal at best, without all the engineering of the OEM's. Those trucks already have a Cold Air Intake from the Fender installed from the factory even though it may not look like it, and the weird looking Induction Tube is also an induction silencer. Some people just have to have that "Throaty Sucking Sound" at WOT!

So appreciate your post fix explanation of manifold vacuum versus fuel delivery. Great trouble shoot tip. Keep doing what you do.

In tech school right now, and I just wanted to say thank you for this video! It has helped me!

Good morning, Mr. O. Very well explained. Thanks for sharing. The only gain from that "cold air intake" was a bill from SMA! 😂

Awesome job again Eric!!!! Best repair videos on RU-vid!!!!

So nice to see you fix a problem, and show the proof of the fix. Smoke machine was a great testing tool on this one! Pretty cool! Thanks again Eric.

I was wondering which leak was the fix until you said air "not accounted for". Now I understand that both areas serviced attributed to the fix. Thanks Eric, very thorough!

I sure wish you lived closer to me cuz you sure in the hell would be my mechanic 😂

So, finding vacuum leaks is all smoke & mirrors? lol

Thank you for the teaching component! I have been watching trims but never thought about Erving to identify vacuum as the issue. I love your videos!

"Aftermarket Junk", LoL!!! You said it best. GM knows that folks need to customize their pickups, so they created a factory "cold air" intake that could be ordered from the dealer from their High Performance division. It works great and helped me squeeze an extra 3hp out of that same 5.3L Vortec. Great video.

I always appreciate how you always track down the source of the problem, and not just correct the symptom. Unlike a doctor who gives you a prescription for pain instead of locating the reason for the pain. Looks like the problem was the vac hose leak at the rear of the engine. Couple tips- a step drill works excellent for plastic and soft metals. And Hardman makes an epoxy/adhesive kit that has single use epoxy packets for many different kinds of materials. Indispensable in your field. Thanks for the video.

Seal the crank case. These PCMs don't miss a trick. V dubs are really high on this. I love fuel trims for this. Aftermarket K&N kits. They work when installed correctly. The concept of "false air". Good stuff, Eric.

Another excellent vid. You use what you have. Mr. O , you are resourceful. I'm always impressed by your scan tool understanding. Years of practice.

You and old Smokey got it figured out,good job as usual brother Eric,your the man bro.Hope all is well with the wife and kids,God bless buddy.

Another option to avoid the gooey mess and aesthetics would be to drill appropriate hole (probably 3/4" or so) and install rubber grommet to receive spigot, pretty much how most pvc's sit on valve covers. Yours is still an innovative solution, nice work.

Just wanna say, this is the best auto repair channel out there by far ! learned so much in the short time i've subbed ! This video teaches us that there are plenty of crap mechanics out there and some amazing ones !

I have been a.backyard mechanic for years. I have been trying my best to learn about the newer vehicles. I can say your are a very good teacher and mechanic. Thank so much for these videos. I have learned so much.

Fair play, I always questioned why you always go straight for the computer first. Quite a few times you've proved it's worth. Hats off to you.

Omg... if I had a dollar for every LS that has had that line off (even on the factory airduct), I'd have a few hundred dollars! So glad I dont have to do this kind of stuff anymore! I'll just watch you to keep fresh on the aftermarket fixings! Awesome job as usual!

"it's only temporary unless it works"......i love that!!

I just wanted to let you know that I've been learning a lot with your videos Thanks

Great video brother. I love drivability videos where you talk about expected data parameters and how they steer the diagnosis process.

Pays to know how the pvc system works. Quite obviously the guy that cut the hose to the fresh air intake and MAF didn’t know what he was doing. I’m sure this guy watched your video to see how you fixed the problem. Good diagnosis. Nice repair Eric

Love the live diagnosis; you said you should have looked at FTP sensor but you didn’t. I feels like I learned with ya! Thinking out loud as you work really helps me out. Would have loved to see ya chuck that puddle sucker into a snow bank lol

Thanks for videos like this got stuck on a 2009 Silverado and your video got me out of a jam found a vacuum leak on their after market air breather. Keep up the great videos.

It is great you are teaching and old 61year old dog new tricks thank you.

You wanted JB Weld Kwik- that's the 5 minute epoxy. I use it a lot, like it.

Great fix, Mr. O! Epoxy compatibility to substrate is an art in itself.....

I like how you say not to clear codes right away! Excellent job on that Chevy. Vacuum leak galore. I don't blame you on a fastener type coming loose then getting sucked into the intake! You are making me not want aftermarket crap on my Ram 1500. Not that I was looking, except air bags in the back for towing. Great Video and showing us the trim and what not.

You appear to be the mechanic that mechanics go to

I installed a K&N cold air intake on 07 5.3 silverado a long time ago, fortunately it came with the pipe for the breather. Never had a lean code on that truck when I had it.

One fitting to think about when punching holes through plastic is the externally threaded metal Schrader valves normally use on wheel rims with tubeless tires. Although they are small, they will go through thin plastic and provide a sealed branch for vacuum lines. You can also manifold two together and use rubber vacuum line and tees to increase the overall flow when called for.

Another great diagnostic process and fix! Thank you Eric!

Love wacthing him work. Admire you Eric!

I would use a brass street fitting when I'm tapping into a plastic pipe like that. The tapered threads make their own threads and a good strong seal in the plastic. For makeshift plastic welding hold a large punch, or cold chisel with vice grips and heat it with a torch. Garbage can lids are a good source for donor plastic. Use the punch like a soldering iron and butter on the plastic.

It's nice to see even the pros have to over come and adapt just like us diy type guys do!!!!

Thank you Eric. Good job. I appreciate your videos. Have a blessed and safe week. Stay warm brother.

Gotta love the hot air intakes. Genius marketing, they just call it cold air instead, then watch em line up

Eric, if you want to rule out the intake skewing the MAF, a vacuum leak between the MAF and the Throttle body or even the MAF itself, just unplug the MAF to put it in speed density mode. Also, if you want to recommend a quality aftermarket intake to your customers that wont throw off the MAF cal, S&B and Air raid will do the trick.

Thanks!! Perfect lesson in fuel trim, I have wrote down every tip you said about fuel trim :)

I would have done something similar to what you did, but it has been my experience that JB weld, plastic, and vibration do not work together, especially when it gets cold, so I broke down and bought a plastic welder. Works pretty well most of the time. Thanks for the video!

Great video Eric O. I've always thought those aftermarket air intakes cause so many problems, the OEM ones are the best. I don't have a smoke machine, I remember my dad teaching me how to find vacuum leaks by using a long piece of hose on my ear and run the other end of the hose all around under the hood (bonnet here is Australia) until you hear the hiss.

you have officially attained master of your trade status.....

Wow you honed in on the problem from the beginning & I'm fine with that fix! Kudos Eric!

When you have 25000 people whach ingredients you in less then a day I tell you Eric you are the superstar of mechanics.great job I am glad you take time to record for us.

I can see the value of having a smoke machine. In the world of DIY I guess we could have used the Paul Danner method of squirting water over everything. But that tube was a dead giveaway. Since watching your videos I have removed aftermarket items on my truck. One less "variable". Great video as usual Eric.

“Aftermarket Garbage” Agree 1,000%! 👍🏽

That's some good info on the fuel trims. You just schooled the owner (tech) as well as thousands of viewers. Good Work Eric!

Thats an awesome repair I have learned so much just watching your channel Thank you !

I remember when I was young and thought the possible 1/2 horsepower gain and all that extra noise was worth it.

Sometimes the Snap-on guy needs the Astro guy to fix their truck .

Five degrees outside. I feel your pain. Use to live in upstate New York. Living in Virginia now. Much easier on the old bones. Another awesome diag video!

Really thorough fix. U liked the way you used ur brain and then technology to back up your hypothesis. Well done Mr. O.

Another great video. Shows how important fuel trim data is to know. Shame that guys get their hands in these vehicles and throw aftermarket parts in there without knowing the basic operation of the system. I get this stuff a lot.

I use a soda can upside down to mix JB Weld... it's dished and makes it easy to mix.

that my friend was very informative. I am working on my brother-inlaws 04 avalanche. same issue with codes. you just gave my direction to look. thank you.

That Plastic Weld works great and is very strong. I've used it mending broken Hinge Mounts on Laptops.

Go to the Pick-n-Pull, get the OEM intake. Lay that Greene pipe on the front seat.

I thought about a “Cold Air Kit “ for my 94 Caprice 5.7 because everyone said I need one then I actually looked at the air box on one of my buddies and realized it was open to the hot under hood air then I looked at my stock intake which pulls air from the nice cool inner fender, hmmmmm think I’ll save myself a few bucks and leave it alone. I did take the home plate off though and polished the intake plenum

Very informative. Absolutely loved the video. It's helping me out alot. Mine I believe is the mass air flow sensor. Did the same as you did and it's still having the issue. Didn't see any vacuum leaks with smoke test. Might do it again and really look behind the motor

Another excellent video. The way you work is finding the root cause and not just swapping parts and guessing.

Excellent. I was thinking a rubber grommet for the fitting.

The guy has a big "Snap-On" sticker in the back window. So apparently he likes the image of being able to fix vehicles more than in practice: "Look at me, I'm so high dollar that I like overpriced tools, yet I can't see this vacuum hose dangling in the breeze."

Thanks Eric! I’ve got a 2002 6.0 with lean codes that brought me to this vid. It came with a “ Kendra and Natalie” junk intake when I bought it. Will use your approach to help diagnose my issue.

I like your explanations, very clear and well thought out even on the fly

There's your problem LADY 😜

20:20 - LOL "One...hour...later..." Love the Spongebob reference

GREATEST TOOL REVIEWS EVER WITH A SIDE OF DIAGNOSTICS THROWN IN FOR GOOD MEASURE NOW THAT IS HOW YOU RUN AN AUTOMOTIVE TOOL REVIEW / DIAGNOSTIC CHANNEL CAN'T WAIT FOR THE NEXT ONE THANKS MISTER O !

I used a rubber grommet last time I did one, it allows the 90 degree fitting to get the grip it needs. As for Fuel Trims, most aftermarket tuners are aiming for +/- 4%.