I have a 92 civic si, and I just swapped in a 95 B18C1. The car ran fine at first, but after a few test drives, started to cut off. Ever since then, the car will start, idle for 5 min, then die, or just start and cut immediately off.

I replaced the distributor/fuel pump/swapped ECU'S, and nothing works. The only two codes I'm getting are 23 (knock sensor) and 41 (o2 sensor). Neither are hooked up yet, but that shouldn't keep my engine from not starting/running.

Can anyone suggest what I can do or try next? Any help would be appreciated!

If you need any more info about the car/swap, let me know. Thanks.