I'm experiencing a persistent misfire on cylinder #3 in my 1998 Chevrolet Malibu 2.4L engine. I've already replaced the spark plugs, but the issue persists. During troubleshooting, I found no signal from the Powertrain Control Module (PCM) to the #3 injector. I tested continuity between the PCM and the #3 injector, which showed a good connection. After reflashing the PCM, the P030
Hi abc505, have you had any recurrence of the P0303 code after fixing it? I'm currently seeing a single occurrence on cylinder #6, and now I've noticed this one on cylinder #3. My engine runs fine, though — I've cleared the code. Does anyone else experience intermittent misfires like this?
Hello piombo, sorry to hear about your issues. I received only a P0303 misfire code and never saw it shift to another cylinder. After replacing the PCM due to an open circuit, my vehicle has run smoothly ever since. Every time I cleared the code, it returned within a few miles. This suggests a hardware issue with the PCM itself — hope this helps others in similar situations.
I took my vehicle to a repair shop, where they diagnosed a faulty PCM. After replacing it with a new unit and re-flashing the software, the P0303 code disappeared and the engine has been running smoothly ever since. This experience may help others facing similar issues.