Fix Subaru misfires
P0301, P0302, P0303, P0304
Subaru misfire problems can affect 1999-06 Subaru impreza, and Forester 2.5L, and also soem 2000-06 Legacy and Outback vehicles. The Subaru misfire can be related to the ignition coil. Before jumping to replace the plugs and wires, check the ignition coil and wires for carbon tracking. Start by checking the coil towers. Look for what appears to be small cracks about 5mm long.
If the coil towers look clean, check the spark plug wire boots where they connect to the coil towers. If you see tracks on the towers, clean them with a clean rag and isopropyl alcohol. Allow them to air dry. Install a new set of wires. Subaru has issued an improved set of wires designed to eliminate the carbon tracking. That should fix the Subaru misfire problem.
© 2012 Rick MuscoplatPosted on by Rick Muscoplat