Tahoe won't coast

[GoodmanOX]

Hey guys. My 99 OBS Tahoe is running rich, I think. The exhaust smells like it, and the MPG is terrible. Also, it feels like it's stuck in a lower gear; it won't coast. What could this be? How do I reset the fuel trim levels/ computer without a scan tool?

 

[Redman7]

Just finished trouble shooting my 99 tahoe with same symptoms. Mine was just the same as yours and no codes detected. my MAF was the culprit. My LTFT and STFT numbers were below -10%. I was told numbers should be no higher than +10% and no lower than -10%. Runs great now.

 

[Danny_Z56]

You could try cleaning your MAF wires with "CRC electronic parts cleaner".See if that makes any difference.

 

[Redman7]

I did try that. it was something to do with the electronics in my case anyhow.