Before you just turn them off I suggest tuning the car to fix the A/F so it runs better rather than just turning off the o2 sensors and covering up the problem. The o2 sensors are there to help adjust the A/F for maximum performance however they can only adjust for 5% in either direction. If your x-pipe is causing more than a 5% sway in the A/F ratio you could be actually loosing power from running lean. My suggestion is to get the SCT tuner and have someone do a tune for you to fix the leanness caused by the x-pipe.
Before you just turn them off I suggest tuning the car to fix the A/F so it runs better rather than just turning off the o2 sensors and covering up the problem. The o2 sensors are there to help adjust the A/F for maximum performance however they can only adjust for 5% in either direction. If your x-pipe is causing more than a 5% sway in the A/F ratio you could be actually loosing power from running lean. My suggestion is to get the SCT tuner and have someone do a tune for you to fix the leanness caused by the x-pipe.
The downstream o2 sensors only monitor the cats, they do not effect air/fuel ratio. How do you turn off the rear o2 sensors, though? I have an SCT tuner and no cats, and I dont know how to do it.
I have a custom tune from LFP for my C&L air intake and off road pipes, but it still sets cat effeciency codes, so the rear o2's are still in the picture
I too have similar issues. I have JBA LTs, off road H and magnaflows. I installed them and didnt know what the heck to do with the two slots nearest to the motor. I was told to plug the fronts and keep in the rears and that the tune would dictate the A/F (told that was the purpose of the tune). I got the steeda CAI and predator 93 and I runs like CRAP. Stock seemed more responsive.
I had Brenspeed turn off the rear (after cat) sensor on my SCT and now it runs great.
It would not even spin the tires from a standing start with the stock tune/no cat off road pipe.
I would before easily and does now easily.
Now the bitch pipe just buzzes so much I am going to put the stock pipe back on. And the exhaust sounded better stock.
I had Brenspeed turn off the rear (after cat) sensor on my SCT and now it runs great.
It would not even spin the tires from a standing start with the stock tune/no cat off road pipe.
I would before easily and does now easily.
Now the bitch pipe just buzzes so much I am going to put the stock pipe back on. And the exhaust sounded better stock.