'02 Running bad, but only in the winter

[chad_towns]

So here is the scoop..


I have a '02 Tahoe with a 5.3L and it runs really rough in the morning especially if it is cold out. The whole vehicle actually shakes real bad and wants to stall on me. After the vehicle warms up a little bit and I drive a mile or two it goes away. The check engine light comes on once in awhile. Went to autozone and had them scan it. Said bank one and bank two are running lean and sugguested possible problem could be the MAF sensor. I took it out and cleaned it but it doesn't make sense. Why does it do this only in cold weater. My truck has 165,000 miles on it but I keep it well maintaned. Had tune up, new wires, coolant flush, fuel injectors cleaned by dealership, etc. Any possible ideas?

 

[Sepiroth]

It does sound like a MAF problem. This could also be an exhaust issue too. Does your truck have any exhaust leaks? Have you changed out your O2 sensors?

Try this. The next time you go out to start your truck, pop your hood and unplug your MAF. This should trip some sort of strategy that is built into the PCM and allow the truck to start and run. IF it starts and runs ok, I would lean toward you having a defective MAF sensor and will need to be replaced.

 

[chad_towns]

It doens't have a exhaust leak as fas as I know.. i will have to try that trick and see if it works. Luckily the MAF is only like $90 so it's not too bad of a repair. Right now I can't afford any crazy repair.

 

[chad_towns]

and I haven't changed any O2 sensors. How many are on the truck anyways ?

 

[flastud904]

hey chad, I will say I had the same exact issue last winter, and yes it was the MAF sensor, it was shaking bad, but I could tell by the sound in the mornings, that it was sucking in air, and I too, went to autozone, and got that read out you did

 

[radkon]

I'm pretty sure the intake temp sensor is built into the MAF on the 02 (I know it is on my 03) Could explain why a new MAF may help.

BTW there are 4 O2 sensors in the tahoe. 2 on each side. 1 in front of the cats and 1 behind. Before you replace any of them have a place scan them and they should tell you which one(s) needs replacing.

 

[oomindwarpoo]

My father in laws trailblazer had the same problem, O2 sensor was bad and the catalytic converter was shot.