1995 850 t5r help with o2 delete (cat removed)

Ricardo · Post by **Ricardo** » 22 Apr 2011, 11:38

I have a green 850 t5r wagon and was doing some performance upgrades. I do have a question someone out there can hopefully answer. I just purchased an y pipe with electric exhaust cut out valve. The only spot that looks straight enough to put it in is where the catalytic convertor is

. If I remove the cat will I get a check engine light? If so has anyone out there found a solution to avoid this. ( Doesn't seem worth installing a cut out down line of the cat)

Post by **Glencoeteen** » 22 Apr 2011, 11:55

can you try and do it right after the cat? if you don't have to go thru emissions where you live then cut it off and get a dummy O2 sensor, I think someone on VolvoSpeed made a custom mod to fool the computer I will have to try and find it. but here in Oregon, in the Portland metro area we have to go thru DEQ Every two years and pass to get Tags. but as far as i know the rear O2 is only checked by the ecu once and a while and that the front one is the only important one to have for the air and fuel mixture, but i am not 100%

Ricardo · Post by **Ricardo** » 22 Apr 2011, 12:29

We don't have emissions testing here. Any idea where I can get a dummy sensor? (tried it find it on VS)

Post by **kcodyjr** » 22 Apr 2011, 14:41

The front O2 sensor is used to control the mixture. You need that working as designed.

The rear O2 sensor is used to verify correct catalyst function. You need to fool that effectively, somehow.