Problem Reports
Report A ProblemProblem with your car? See what our experts say or submit your own.
2004 Subaru Forester
Check Engine Light Due to Failed Catalytic Converter
The Check Engine Light may illuminate because of low catalytic converter efficiency. This same issue may cause the car to fail the State Smog Test if one is required.
Check Engine Light Due to Failed Knock Sensor
The Check Engine Light may illuminate because of a failed knock sensor. Although the sensor often tests okay, it can fail intermittently, while the vehicle is being driven.
Engine Misfire Due to Failed Spark Plug Wires
Sometimes the Check Engine Light illuminates because the computer detects misfires. Subaru released an improved spark plug wire set to solve the problem. The ignition coil should also be inspected for carbon tracks or short circuits between the contacts
Engine Misfire Due to Oil in Spark Plug Tubes
An oil leak can develop from the spark plug tube seals. Excess oil in the spark plug tubes can result in engine misfires and illumination of the Check Engine Light. Our technicians tell us that removing the valve cover and replacing the tube seals and cover gasket is necessary to correct this concern. Oil damaged spark plugs, ignition wires, and ignition coils will also require replacement.