u/Upstairs-Spirit-2958

CEL with no catalytic converter

Pulling code P039/P0140 and had several people saying to replace the downstream O2 sensor. However the catalytic converter nor “downstream” exist due to a straight pipe swap.

Does anyone else have experience with converting to straight pipe and having CEL be persistent?

reddit.com

u/Upstairs-Spirit-2958 — 7 days ago

▲ 23 r/mazdaspeed3

Naive of me to think that the tuning would be the most straightforward part of the process of getting my car back on the road?

Because it too is becoming quite a lesson in patience.

u/Upstairs-Spirit-2958 — 9 days ago