O2 Sensor Code Wont go Away
 

ok my car has a CEL for the O2 sensor and i have an aftermarket ehxaust and header with the stock down pipe on my 02 elantra now idk what to do to make the code go away beside put the bung for the sensor back further and behind the the cat on stock down pipe. know i know there prob a solution and i prod didnt look down the fourm enough but is there anything else i can do?

It's easy. All you need to do is go to your local advance auto and get a spark plug antifouler. Drill the antifouler out with like a 1/2 drill bit so the o2 sensor can fit in, then reinstal the 02 sensor with the antifouler attached. I have had no problems with my setup and it still runs the factory afr. Even passed inspection twice.

ok i will try this and let you know if it helped at all

^^ up here ,we call them "defouler's"...same thing.

heres an update this past wed i started my car in the morning to go to work and i noticed that the CEL wasnt on so i stoped at my machanics and he pluged the car in to his computer and looked at my O2 sensors and conformed for me it is the secondary one and that the way i have it its out to far from my exhaust so im gonna an get an spark plug antifouler and see what happenes

ok i got the non fouler and drilled it out abd put it on and now the scanner reads the o2 sensor holding at 425 and not flusuating and also the CEL came back on so idk whats with this car but i looks like im gonna have to get my own custom exhaust built

if its reading a steady voltage then either its not seeing any exhaust stream at all or your O2 sensor or wiring is toast w/o butter.

A steady reading like that means you have a wiring issue or dead o2. Even with the non foulers on your car you should still get some fluctuation on the readings.