Ok, here's the specifics that I have. A 1990 Acura Integra, with a 98 (supposedly?) b18b1. When its warmed up, at 3250k it will just backfire for maybe a second total...real quick like, then go away. I *THINK* the guy that did the swap, used an OBD2 brain, with the OBD1 wiring (is that possible?) and I know that he did not have the o2 sensor hooked up. Any ideas what I can check first to see what the cause of the hesitation/backfiring is? I know he mentioned that the plug for the o2 sensor was different, and in a different location, and I'd like to fix this eventually. I'm wondering if the two issues are related. Any advice on what could be going on? Thanks!