1,200 Mile Road Trip - P0171 / P0174 / P0300 Engine Codes

[Doubeleive]

my experience with part of that is a dirty or beginning to be faulty MAF will cause a lean code, but the misfire is a whole different thing, I started having issues with mine after installing a cai but that's just my experience I could get away with cleaning it for a while and sometimes it would go away for a couple weeks and sometimes it would come right back on. replaced the maf and problem disappeared. I only figured this out after replacing $75 o2 sensors one after the other and kept getting the same codes.

 

[mals]

my experience with part of that is a dirty or beginning to be faulty MAF will cause a lean code, but the misfire is a whole different thing, I started having issues with mine after installing a cai but that's just my experience I could get away with cleaning it for a while and sometimes it would go away for a couple weeks and sometimes it would come right back on. replaced the maf and problem disappeared. I only figured this out after replacing $75 o2 sensors one after the other and kept getting the same codes.

Hmmm, I did install an Airaid MIT tube last spring a few months before I started getting these codes. I don't think I read any reviews of the MIT that mentioned issues after install. I wonder if it was enough to reveal another issue that was hidden (MAF, intake gasket, or O2 sensor).

 

[mals]

Have the spark plugs ever been replaced?

Spark plugs were replaced 9k ago when I bought it, but I didn't replace the wires or coils at the time. They all looked good and I needed to put the money elsewhere when I was getting it fit for the road.

 

[Doubeleive]

it wouldn't be any kind of recall issue its just that the MAF can get dirty especially if you using a oiled filter like a k&n and it cant read the air right so it causes a code, it's a good idea to clean it atleast every once in a while anyway, it only take a couple minutes the cleaner comes in a aerosol just pull it off, hit it with the cleaner and wait till its dry the chemical cleaner dry's out fairly quick, I used to hit mine with the air compressor at the same time, don't stick a brush or ANYTHING in there it's a very fragile wire inside just spray it out and let it dry

 

[mattbta]

Hmmm, I did install an Airaid MIT tube last spring a few months before I started getting these codes. I don't think I read any reviews of the MIT that mentioned issues after install. I wonder if it was enough to reveal another issue that was hidden (MAF, intake gasket, or O2 sensor).

It took me several attempts and several settings of lean code to get my MIT properly sealed at the TB. It would work a slight bit loose and suck in unmetered air.

 

[mals]

the MAF can get dirty especially if you using a oiled filter like a k&n and it cant read the air right so it causes a code, it's a good idea to clean it atleast every once in a while anyway

It took me several attempts and several settings of lean code to get my MIT properly sealed at the TB. It would work a slight bit loose and suck in unmetered air.

I'm still using the stock paper filter, so the MAF shouldn't be fouled with any oil. However, I may may pull the MAF and the MIT to check both. Can't hurt to clean the MAF and make sure the MIT is properly seated on the TB. If that doesn't do it I'll try 02 sensors, and then move on from there. I know throwing parts at the car is not the best diagnostic approach, but I figure most things on my Yukon appear original, so I'd rather know they are not the cause of this or a future problem.

 

[Potch]

I just had the same codes pop up on my 2002 this morning on my way to work. P0300 (random/multiple cylinder misfires), P0171, P0174 (both banks too lean) and also a C0281 (Brake Switch Circuit).

I'm also a fairly new 2nd owner and everything was original. Bought it in Feb of 2017 with 131k miles and now I'm approaching 138k.


Did you get your problems resolved? I am looking at replacing the fuel filter, spark plugs and plug wires because they probably need to be done and are simple and affordable. I'll also check and clean the MAF and check for leaks or loose fittings in the intake system and gaskets. If those don't resolve the issue I'll do some more research and see what else I can find.


Edit: It has been dipping into single digit temps the past couple of nights.

2002 Tahoe LS, 4wd
5.3 L
138 k miles