Yesterday while at the local Pick-And-Pull, I came upon a freshly placed 1992-1993 Integra. So I grabbed the transmission (my synchros are thrashed - I hope this one is better) and PR4 ECU (possibly to chip). To see if the ECU works, I swapped it out for the P75 I was currently using for he B20. And the results were quite unexpected. First of all, the hesitation I have never been able to get rid of disappeared. Idle smoothed out (although I had to turn up the screw). Power is increased across the board - especially in the low end. And gas mileage seems to be better. So what is going on here? I have always heard the OBDI PR4 is basically the same as the P75. Yet, my B20 is running ALOT better with the PR4. Can an ECU be bad enough to make an engine run bad, but not bad enough to throw a code 0? Or is the OBDI PR$ actually a better ECU than the P97?

 

bump, i'm running a pr4 ecu on my stock LS right now