So I have had a PPE long tube header installed for a couple years. The rear O2 extension wire was too long for how I routed it, so I had it loosely coiled and zip tied to the bracing until recently. I kept getting the occasional P0131 code every few months, and the exhaust would rattle at idle.
Anyway, I recently adjusted the exhaust to stop it rattling. I checked the O2 sensors, and the front one was loose, so I tightened it. I rerouted the rear extension wire to go to the other side of the car, over the transmission, zip tied to the brake lines. If I understand the installation instructions here correctly, that is how it is recommended to be run. I thought the wires looked good, undamaged and not pinched. Connectors looked good and were connected solid.
But now I get immediate CEL when I drive the car. I get P0131, P0139, and P2096. If I clear them, they come right back the next time I drive.
Could the extension wires be bad? Is there a way to check? Should I replace the front O2 sensor since it was loose and is the most likely part to be damaged?
I am getting codes for both O2 sensors, so I'm not sure what to look at first. Replacing both sensors and extension wires would cost a few hundred dollars. It is also not fun working underneath the car, so I hate to keep trying things over and over.