Car came into my shop with a misfire, the owner put new plugs and wires and cap and rotor still misfire. I checked codes has 304 (misfire # 4) (and another code also something like: lost of class 2 serial data??) ( I figured he unpluged something with the key on while doing the tune up.) I checked the wires for proper install and made sure the plug was not cracked or dropped and van has good spark. Then I replaced the injector. Now van is still missing. I am thinking the injector is not getting a pulse? Which is hard to check on these vans? Anyone have an idea about that, I guess I will have to cut the wires to check for injector signal. Otherwise could be a bad connection or corosion at PCM or broken wire or no compresson, I will check compresson tommorow. I doubt this only 90,000 miles. Anyone have any other idea or have a problem like this. Anyone see a bad PCM do this before?