o2 sensor location

[e-dirtym52]

i was wondering what the best place for an o2 sensor its. i don't know if i put mine too close because i think i might have burnt it out pretty quick from backfire. so i don't know if it really matters where it goes or if it's too far up. i have it right after my downpipe. basically the same location as the stock 325i had it. does it need to be back farther maybe?

[frankie591]

You want it as close to the start of the system as possible while still sampling all 6 cylinders. I have mine in the y-pipe right after my long tube headers.

[e-dirtym52]

well my engine backfires quite a bit and i think i might have fried out the o2 cause it's throwing an 02 code and a lambda control code. so if i move it back more towards where the cat would be would that effect it at all? where it's at right now is right after the down pipe. actually now that you mention sampling all 6 cylinders my o2 sensor bung is only in one pipe. it's not sampling the other cylinders because it's still in dual pipes. i'm going to y pipe it this weekend and run a 2 1/2 inch catless all the way back. so i'm guessing i'm going to have to move the o2 to where it gets exhaust from all 6 cylinders and not just 3 huh?