So I've pulled the CEL and it comes up as one short blink indicating a problem with the primary o2 sensor. I have no idea why this is occurring. I recently switched back to a p13 ecu from a chipped p28 and this is when the code started throwing. Unfortunately I sold the p28 before I realized I would have this issue.

I'm running an 01 h22a4 with the original wiring from the accord so it is all obd1. Everything else runs great. FYI, injectors and all have been converted to obd1. Can anyone with a helms manual post what the diagnostic process is to figure out this CEL? I've replaced the o2 sensor twice with new ones, bosch and denso, and it is still throwing the code. Could the IAB be causing the code? The cat is also new so I don't think that could be doing it either. Any help would be greatly appreciated.

 

Did you extend an wires on the O2 sensor?

 

Would that cause a problem? The wires on A6 and D14 were both extended back in the day at the harness plug to the ECU. I used a basic 16 gauge wire soldered them to make sure neither were loose. Both are for the o2. At the time of the swap I was errantly told to cross those wires with each other and did so. After that I switched them back after I found out that was incorrect. Would the larger wires cause the wrong ohm or volt reading? There was so little room to swap them which is why I did so. Why would'nt that cause a problem back then though? The o2 sensor CEL only came on after I switched back to a p13. Thanks for your help.

 

Removed the extended wires and resoldered the original ones together and reset the ecu. Still getting the code. I did notice a small fraying in the flex pipe of the header downpipe. Could that causing the CEL? Will try to get some exhaust tape/wrap to see if that helps.

 

Bump for some help.