X2jesse1x

I recently purchased an 08 GSR with no catalytic converter. And service engine light is on. Unfortunately I live in a county that requires emission testing, so I need to install a cat.

The car has a straight pipe welded in place of the cat. I took the car to advanced auto to get scanned and I got the following codes:

p0172 system too rich
p0139 heated oxygen sensor (rear) slow response
p0139 heated oxygen sensor (rear) slow response

I am assuming this is due to the cat being removed. I don't know how I got two of the same code though.

and when looking under the car it looks like the rear o2 sensor (under passenger seat) is installed in the front on the down pipe with a spacer. I don't see the front o2 sensor at all, but I don't have a code for it so I'm confused.

317Speedworks

Rear shows 2 because one is pending and one is confirmed. The "spacer" is a defouler. Cheap way to theoretically get the light turned off, which apparently didn't work.

I'm not sure about Evos but some cars run intermittent max fuel trims to check the rear o2 to see if the cat is doing it's job, throwing a rich code of it continually max's trims, since there's no cat.

X2jesse1x

Any idea why the rear o2 would be in the front and the front o2 is missing?