that's a pretty good one.
I used to have a engine misfire problem. replacing spark plugs only worked for a short time then the engine would misfire again. Then I used the scantool which I built using a laptop running PCMSCAN_2.4.5 to monitor the engine. I noticed MAP reading sometime jumped out of range. replacing the MAP sensor fixed the misfire problem.
BTW, the OBD code didn't indicate MAP was the problem.
