The front oxygen (air fuel ratio) sensor element may develop a crack, causing the Check Engine Light to illuminate. Subaru has recalled certain models to replace sensors that may fail. The Subaru service program number is WXW-80, this is not a government mandated recall.
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.
The head gasket has a high failure rate due to cooling system problems. Subaru is aware of the problem and has extended the warranty to 8 years/100k miles on many vehicles.
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.
Front engine oil leaks can develop from the camshaft seal and the crankshaft front seal . If one or more seals require replacement, it may be wise to consider replacing the timing belt as well. These seals are commonly inspected and replaced as needed as part of a timing belt service.