I'm needing to replace my rear o2 sensor. that's behind the cat right? my car is still in the body shop, so i cant go under and look just yet.

also, is there a difference between the o2 sensor at the headers and the down-stream sensor? I think i might just do a little preventive maintainance and replace both at the same time.

umm o2 sensors on the sr20 are only like 40-50 bux each.. not bad at all

where can you get them for 40 bux?

JUST GO TO OREILLYS AND PICK ONE UP BUT DONT GO TO NISSAN CASUE THE ARE BOTH MADE BY BOSCH ANYWAYS, NISSAN JUST LIKES TO RIP OFF THERE CUSTOMERS JUST LIKE EVERY OTHER CAR COMPANY.

ya, they're only like $52 or so. not too bad.