OBD2 P0303 Misfire Code in 2001 Jeep Cherokee - Causes and Fixes
I recently replaced the spark plugs in my 2001 Jeep Cherokee, but now the vehicle is showing a P0303 OBD2 diagnostic code indicating a misfire in cylinder 3. The engine runs smoothly under normal conditions, which has led me to wonder what might be causing this issue. Could it be related to the spark plug type or installation? I'm looking for accurate troubleshooting steps to resolve this problem without unnecessary repairs.
You didn't specify the engine type — could be a 4.0L, but that's an assumption. First, confirm you used the correct spark plug brand and specification for your 2001 Jeep Cherokee model. Double-check your installation process to ensure proper seating and gap settings. Try swapping the spark plug from cylinder 3 with one from another cylinder, then clear the P0303 code and monitor if it returns. This helps determine whether the issue is in the plug or a different component like ignition coil or fuel delivery.