Chevy pickup problem

[Dana Warner]

Sounds like a MAF problem or an intake leak after the MAF. Low fuel pressure is easy to check too.

 

[flusher]

O2 sensors rarely go at the same time like that and if they did, you would see a code for at least one.

Since both sensors are reading a lean condition then the problem is something that affects the engine on both banks. I think it's still a MAF sensor or intake leak. I've received bad MAF and other electrical parts from stores before.

If you have the old MAF, plug it in and see if you get the same symptoms as before. When is the last time you cleaned the K&N? Is it possible you over-oiled it?

K&N is touchy on this subject

K&N Response to Mass Air Flow Sensor Concerns

 

[yasureyoubetcha]

My friends pickup{also a 2005} did the same thing after I installed a K/N filter system for him, s.e.s. code said lean on banks 1&2, put the original filter back in and no more problems. It did run ok tho...

 

[kf4uda]

Odd timing for this post. I have a '03 GMC Sierra with a 0171 code on it. I am running a K&N filter on it as well. I just finished cleaning the MAF with CRC Mass Air Flower cleaner and then reset the code. I have had this problem before so I am fairly confident it will fix it.

I think I am going to dump the K&N filter and go back to a stock filter. I am not necessarily bashing K&N as it could be a case of me over oiling the filter.

 

[timswi]

I've run K&N's in my last 4 GM pickups and never had a problem...Odd though that it appears that the dealer removed the K&N warning sticker when I had it inspected...Was going to call and complain, but I forgot about it...I'll argue with that tech anyway, he put a 12/12 inspection sicker on it with a 12/13 emission sticker...I'll argue eyesight

I've had one in the wife's Hummer for 3 years and never had an issue.

 

[Diamondpilot]

I've run K&N's in my last 4 GM pickups and never had a problem...Odd though that it appears that the dealer removed the K&N warning sticker when I had it inspected...Was going to call and complain, but I forgot about it...I'll argue with that tech anyway, he put a 12/12 inspection sicker on it with a 12/13 emission sticker...I'll argue eyesight

I've had one in the wife's Hummer for 3 years and never had an issue.

I am with you. I have had them on 15 or so Fords, 1Nissan, and 1 GM with no issues. Some were K&N and some were other brands such as MAC.

Chris

 

[lostcause]

i used to have a 2000 chevy 2500 crew (classic style) with a 5.7 that i bought used in 2002 from a gm dealer. it had a k&n filter on it when i bought it, and I had used them before on bikes & atvs with good results, so i left it on. a few months later i started having issues with it stuttering under load, like when pulling out into traffic with several thousand pounds on a trailer behind it.

i took it to the selling dealer and explained the issue, and eventually they were able to reproduce the problem so they knew i wasn't crazy. the problem was that they couldn't figure out what was causing it. that vehicle probably didn't have anywhere near the onboard diagnostic abilities and sensors as the newer ones, so it wasn't throwing any codes to lead toward the problem. eventually, after a few calls to gm tech, they got a guy who out of the blue asked if it had a k&n filter. that ended up being the problem. apparently, small amounts of oil was bleeding through the filter and adhering to the mass airflow sensor, then tiny particles of other contaminants adhered to the oil coated wire in the sensor.

this coating obscured the wire so it was getting an incorrect reading and adjusting the fuel mixture improperly. after cleaning the mass airflow sensor and replacing the k&n with a stock style filter things were all better. as another poster said, it's not a complaint against washable filters - it could have come from over-oiling of the filter, or maybe even a lack of maintenance. i've used them before and i'll use them again, but probably not in a fuel injected vehicle. i don't need the extra airflow in a stock vehicle and i don't think long term reliability will suffer from a stock filter, so for simplicity's sake i'll keep going with the paper elements.

 

[deerehunter/operator]

At our GM garage, we see problems fairly often with K&N filters coating MAF sensors with filter oil. Cant count how many times especially on the Duramaxes. Put a stock filter in it and clean or replace MAF again.

 

[murphy1244]

The reason your showing a lean condition is the K& N filter allows more air thru. On my 70 chevelle I had to rejet and reset idle screws.

 

[kf4uda]

So far cleaning my MAF has worked. The code has not come back but I have only put about 80 or so miles on my truck. I have not done anything with K&N filter yet. I may just clean and re-oil it, taking a little more care this time and not over oil it. I still think that I over-oiled the filter.

Not related (except the same truck) but looks like I will get to install a new water pump tomorrow. Making noise and leaking from the weep hole...oh joy!

How is the problem coming with your truck Todd?