I put a megan downpipe, ultimate racing high flow cat and magan exhaust and got a cel light on all it sed was bank one #2 sensor which is rear so i bought the perrin light hooked up it the little red light came on but day later cel came on so month later i bought the ebay one ... the one that takes it out of the exhaust stream probably 20 minutes later light comes back on... do i just need to replace the rear 02 sensor or am i just dumb please help thanks sorry if this is alil off topic but just needed some help

 

I had to experiment with the different lengths of the anti-foulers to get the right distance for the o2 sensor to be out of the stream but still sniff and not get a CEL.I nicked the cover of the o2 sensor and exposed the wires and no repair fixed the CEL.Bought a new o2 sensor.Not cheap!

 

so all you did was replace... if i replace with new do i have to take out the o2 fixes or just but in the new and it will work

 

I replaced what I had ruined.The new o2 sensor did not change the CEL.The anti-foulers come in different lengths so I experimented until the CEL stopped.I had to use one short and one long.

 

YOU NEED TO GET THE CODE(S) PULLED TO KNOW WHAT IS WRONG (ie bad wiring if you pu an elect fix in or sensor seeing too much exhuast)

You can buy them on Ebay for 30 bucks.