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.