I have a 1992 civic si with a 1999 Acura Integra motor (B18C1) that has been converted to OBD-1. When I bought the car it had a P-28 still in it. I just got my OBD-1 P-72 ECU and plugged it in and went for a ride. After about 10 minuets the check motor light came on! WTF! So I calm back down and put the p-28 back in to drive home and then after I start the car it throws the check motor light again! I dont know what to do. It does not throw check motor light on right away after I start it with the P-72, it only does it after I take the motor past 4,000 RPM.


PLEASE HELP!

 

https://honda-tech.com/zerothread?id=798020

I posted on your cii thread too.

 

knock sensor. If its missing broken it could be it. It only checks for it once your engine is warm. Your P28 might have been chipped not to look for it.

just a thought