Originally Posted by knuckles27
Went to AutoZone last night. I left the ticket in my car but I am pretty sure the code was P0240 for the cat. This is right in line with the Subie dealer thing the SPT exhaust was causing a false positive. They are installing an Access Port and tuning the car on Monday.
It sounds like the car has an aftermarket Downpipe since a catback SPT exhaust should not affect the p0420 Catalyst efficiency code. The AccessPORT will let them deactivate the light.
Food For Thought
Depending on your local emissions it may not be a bad idea to take it in for testing at Motor Vehicle to make sure it passes with the stock DP. This is in assumption the car has a stock DP with both cats in it. I failed Colorado emissions with an aftermarket DP and had to install a factory DP to pass. If your factory DP + AccessPORT Tune does not pass, then you are looking at a spendy bill to get it to pass. Better to act on it now, while the dealership is still held accountable, versus 12 months from now when emissions may be due and you are on your own financially.