When diagnosing a misfire code(s) P0301, P0302 P0303 and/or P0304, there is the possibility that the ignition coil and/or high-tension cables could be the cause. In addition to the information published in the service manual, use the following procedure to check the ignition coil and high-tension cables.

Applicability: 2000 and later Legacy/Outback 2.5L SOHC vehicles; and 1999 and later Impreza and Forester 2.5L SOHC vehicles.

New-style high-tension cables have been used in production since the VINs shown:

Repair Procedure:

1. Check the tower portion of the ignition coil for carbon tracks (leakage). If leakage is more than 5mm long, the ignition coil and high-tension cables should be replaced.

2. Check the high-tension cables for carbon tracks (leakage). If leakage is evident, replace the high-tension cables and clean the ignition coil.

3. If there is any evidence of carbon, clean the surface of the ignition coil using a clean, soft rag dampened with water.

4. Allow the ignition coil to dry.

5. Clean the same area of the ignition coil using a clean, soft rag dampened with isopropyl alcohol.

6. Allow the ignition coil to dry.

Note: Do not insert the high-tension cables until the ignition coil is dry.

Parts Information:

The high-tension cables...