so i got my longtubes on and i went 3 inch no cats in to a y pipe and out right before the rear tire.. not keeping it like this but had to do something to drive it... now my problem is.. i have the two before the cat O2 senors in the headers... but dont have a place for the two rear O2 sensors.. so the SES light is on!! (and its running like *** lol) going to be running an x pipe and dumping it right after axle.. so what should i do with the O2's.. thanks guys..

 

Typically you would use tuning software to turn off the rear O2 sensors. They aren't needed for the actual running of the vehicle, just for emissions checking. You could also get some "O2 sims" or simulators, which plug into the harness and fool the computer into thinking the rear O2s are running fine.

Removing rear O2s won't cause your truck to 'run like ***'. How do you know its misfiring? Do you see the blinking SES light while driving? If so, I'd bet you bumped a spark plug too hard while changing the headers and its broken, or you broke a plug wire or terminal when removing them. I learned this from first hand experience. If you don't see a blinking SES light, then its probably not misfiring. I'd start looking for exhaust leaks around the headers that are contaminating the readings to the front O2 sensors. That would cause the truck to be overly rich and 'run like ***' too.

Good luck. Oh yeah, nothing wrong with using a Y pipe either. Unless your stuff is setup just right, you won't see major gains going to a X pipe from a properly sized Y pipe. It will just hurt your wallet.

 

well i had 2 random mis fires.. it blinked two didnt times so i went to auto zone to get it checked and thats what it was... and its so wierd.. sometimes its misses at a stop but as soon as i start going its fine and then sometime its fine.. its on and off.. why in the hell would it do that lol... oh and one more thing.. i gonna get some NGK plugs with MSD spark plug wires.. do i need those little heat shields that are by the headers?? thanks