2002 Nissan Quest P0300 P0325 P1105 Misfire Diagnosis and Repair Guide
Our 2002 Nissan Quest has been displaying persistent misfire codes: P0300 (random/multiple cylinder misfire), P0325 (spark plug wire or ignition component failure), and P1105 (MAP/Baro Switch Solenoid Valve fault). The vehicle has been running poorly, especially after rain or humid conditions. We've already replaced the distributor cap, rotor, and spark plugs along with wires. Despite these repairs, the issue persists. Now we're considering replacing the distributor—however, before doing so, are there any other potential causes we should investigate? Any guidance on diagnosing or repairing P1105 specifically would be greatly appreciated.
Start by inspecting the MAP/Baro Switch Solenoid Valve (P1105 code). Check all vacuum lines for cracks, loose connections, or leaks. Ensure proper vacuum pressure is maintained. Also verify 12 volts at the solenoid with the key off engine (KOEO) to confirm electrical integrity.