Impreza Outback Sport AWD F4-25L SOHC (2002) Spark Plug Removal and Installation
Spark Plug: Service and Repair
Cleaning
CLEANING
Clean the spark plugs in a sand blast type cleaner. Avoid excessive blasting. Clean and remove the carbon or oxide deposits, but do not wear away
porcelain.
If deposits are too stubborn, replace the plugs.