Gentlemen,
I have stock 2000 Impreza RS 2.5, that runs like s**t. It's hard to start, taking about 4 seconds, normally when warm, usually not when the engine is cold.
The check engine light has been on for a few months, and I took it to AutoZone to have the codes read. All four cylinders are showing misfiring, and the "catalyst efficiency below threshold" code also came up. The code numbers were P0301, PO302, PO303, PO304 and PO420, I believe.
So, I changed the plugs today and put in the NGK plugs recommended in the Owner's Manual. The plugs I replaced were the same type, installed 11,000 miles ago. At that time I also had new ignition wires and coil installed.
This may be unrelated, but I also had a new exhaust system installed from the catalytic converter back about a month ago.
Possibly, I need a to catalytic converter. But, there may be something else going on.
I am at the point where I'm considering selling this baby. I just sold a Honda Civic VX today, and with 140,000 miles it still runs great. But I really would rather just be able to get the Subie running well again.
Any suggestions for the cause of the problems, or encouraging words, are appreciated.
Regards,
Randy Olson
Ithaca, NY