My '05 2.5i (NA) is throwing a P0420 code. (Catalytic converter under threshold) It has 146K miles on it.
Around 2007 there was a recall on the car, I got a letter saying the ECU mapping causes the cat to heat beyond its tolerances under certain driving conditions, so I was asked to bring it in to the stealer to have have the ECU re-mapped, which I did.
Around the same time, at around 50K miles, I got a CEL with the P0420 code, so I took it in. Both the L and R cats were replaced under warranty.
I called up the stealership (Putnam Subaru in Burlingame, CA) and explained the situation, and they said there is a $100 charge to diagnose it, which will be waived if the repair is under warranty, but if it's not covered I have to pay the $100 charge.
$100 to take 30 seconds to put a code reader on it and take peek at the cats seems excessive to me -is this standard practice? I don't remember being charged any diagnostic fees last time this happened.
I believe my car is a CA PZEV model (it doesn't have a "PZEV" badge, but aren't all '05 NA's PZEV?), so it should the California Super Ulra Low Emission Control Warranty, which states "For 15 years or 150,000 miles (whichever occurs first from the time of retail delivery of your vehicle): . . . 2) Subject to the specific terms pertaining to maintenance below, if any emission related part on your vehicle is defective, which would cause the vehicle's Onboard Diagnostic malfunction indicator lamp to illuminate, the part will be reparied or replaced by SOA, Inc. This is your emission control system DEFECTS WARRANTY."
I understand from browsing these forums that P0420 could mean bad cat(s) or possibly a bad rear O2 sensor. Cats are clearly emission related, but is the O2 sensor considered an "emission related part?"