So my car at idle is blowing black smoke and is running super rich.There is a huge lack of power and is jerky when trying to drive and when it idles it seems to want to die.Im not throwing any cel lights which is wierd but Im thinking o2 sensor because I am trifecta tuned with a DP so my code is disabled.If it is the o2 sensor what sesnor is that because gm parts directs shows an upper and rear oxygen sensor? thanks guys

 

do u have an afr gauge??? u wont be able to tell what o2 sensor it is unless u throw a code... but most likely its bank one...

 

No afr guage and no real way of knowing if its my o2 sensor but I checked all wiring and everything seemed ok just trying to get some second opinions before i drop money on an o2 sensor

 

get it fixed as fast as possible cause u will clog ur cat very fast...

 

Just because the MIL light isn't on doesn't mean you aren't throwing codes.

 

I think you're thinking of the rear O2 sensor, which just measure catalytic converter efficiency. That is the code that is disabled. That sensor would not cause your car to run rich. It just tells you whether or not the cat is working.

 

You bank 1 sensor will throw your car off. This happened to me a little while ago. It would chug on idle and spit and sputter when I drove it. My car still has warranty so I took it in and they put two new sensors on and it ran like new again.

 

Same for me, if you don't have a warranty I can get the o2 for $70 vs the $130 they go for