Chevy pro's- Check engine light continues to come on in 2008 suburban 5.3 4x4. 110,000 miles. I am not mechanically inclined.
My mechanic(s) can't resolve. Here is Play by Play:
1. Idling rough and low gas mileage this summer at 90,000 miles so i took in for tune-up... also had "performance" goo in engine to clear carbon out?
2. Next day check engine light on.
Take it back and it is oxygen sensor, they reset light, comes back on in a day or two. 3. take to different mechanic they replace OS. 4. 3rd mechanic- Light back on- catalytic converter and another OS... replace another OS. 5. Light back- catalytic converter... replace the converter. 6. Light back- OS... they "reflash" computer with updates... light stays off for couple of weeks. 7. Light back- codes C.C., OS, vaccum leak, fuel pump... replace gas tank vent. 8. Drove 9 miles til light came on... codes Catalytic converter (already replaced).
Truck runs ok. Gas mileage down about 10%. Stumbles at idle occasionally. feels sluggish. What was a great truck, is now a Lemon/ nightmare/ money pit. Any suggestions or help would be greatly appreciated. Don't make me dump this one on some unsuspecting Ford dealer in trade for Expedition.
Thanks, Dave

 

Welcome to the forum.

Sounds like you need some new mechs. What was the "performance goo"? That may have been the beginning of the end for the O2 sensors and the cats.

 

It was a chemical to be run through the motor to clean out carbon and injectors etc. Can find out more tomorrow.

 

If it was BG or Techron, I'd be a little leary. Good luck.

 

What are the code numbers?

 

I have to replace bank 1 sensor 1. I have the part, I have the tool to remove the old sensor. What I can't figure out is how to remove the blue plastic locking tab on the connector without breaking it as well as the plastic push tab that holds the connector in place. Any help would be greatly appreciated.

Thank you!

 

Sounds like a vacuum leak, making your o2 sensors read lean, thus your injectors dump more fuel.

O2 sensors that show fluctuations from. 000-.999 volts is good. Your mechanics need to get your fuel trim readings. +\- 10% is ok, but I suspect its way higher.

Common leaks are front and rear end gaskets on intake manifold.

This could explain your new cat code. Its full of raw gas and carbon. I suspect your tail pipe is severely carboned up too.

Just my opinion without actually seeing live data.

O2 sensor codes, as well as many other codes, doesn't always mean its bad. Proper trouble shooting will save a lot of money.