I'm buying catalytic converters kit online and having my mechanic put it on. Two spots for sensors. Can I use universal O2 sensors on both or do I need specific sensor for each one?? It also looks like sensors online are much cheaper than at auto parts stores. Any opinion?

Thanks for the help

you could get away with a universal downstream for the rear. I would recomend against it tho. The upstream you need an OEM type sensor. IIRC OEM is Denso, and I would stick with Denso. You can get an aftermarket Denso, or one from the dealer. It is VERY important since the upstream adjusts the air/fuel ratio and the ECU is programmed to adjust from a set of ranges. If those ranges are off, it could run bad or throw a code

Recently replaced the up stream O2 sensor on my 99 OBW with a Bosch oxygen sensor part # 13702, after CEL thru a code that the oxygen sensor was bad. The Bosch sensor works great, with my car running better then before the CEL. With on line discount coupon, cost from Advance Auto Parts was $59.XX.

I have a couple good CATS in Colorado that would bolt right in.