Thread: Decatting a grand prix. Rear O2 sensors....

Originally Posted by FoSHO99

01+ goes into a CAT diagnostic when the rear 02 is deleted by code. It will sometimes cause the LTFT's to fluctuate back and forth and may cause the car to surge, it is testing the CAT. The only way to disable this is to run an 02 emulator or install the rear 02 so it is not directly in the exhaust stream or disable this diagnostic using a program called tiny tuner.

It doesn't run this test at all times, just when it feels the need to run this test, then goes back to normal.

That explains my surge issues,thank you so much. Will have the tune modified,seriously I thank you.

Originally Posted by FoSHO99

How often and how much did your car surge though? I ask that because most times this test is ran, not too many people notice or realize their ltfts are fluctuating, unless you are scanning or keeping a constant eye on it.

It'll surge like I put the cam in already lol and at times die out. My exhaust is'nt stock by any means so when it surges I could tell lol. So could my neighbor.

I'm going to try and get it retuned this next week,i wonder if that test is messing with my front 02 since when it does it I get the great 1133 code. Hmm?