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Hello, I have a 2007 Corvette 6 speed 6.0 base model, and i keep getting the cat codes P0420 & P0430. I have changed out both cats, I have change out all 4 of the 02 sensors, but the code just keeps on coming back. The car runs really good, everything on it is stock, I am just trying to get it to pass smog. Any one here encounter this same issue and how have you fixed it? Please any advise is greatly appreciated.
The P0420 and 0430 is one of the top 5 DTC’s…a bad cat is an “effect” and not the “cause”…things like misfires that if left undiagnosed can degrade the cat and cause this…have you put at least 100 miles on the new cat because it needs to be “broken in”….did you buy an aftermarket or OEM cat…aftermarket cats don’t have the amount of precious metals in them that allow the cat to function properly…has the car had any exhaust work lately as an exhaust leak anywhere between the upstream and downstream cat can set this DTC…there are other causes of things that will degrade the cat other than misfires are excessive blowby or coolant contamination…I’d find a shop that does purely diagnostics as general repair shops and dealerships aren’t equipped to accurately diagnose these DTC’s !!…they only replace parts and that can get expensive…where are you located as I may know some diagnosticians in your area.
Most shops are not good at diagnosing so I’d search one of those out…is your cat OEM or aftermarket ??…being in California your cat must be CARB compliant and not all are…are your O2 sensors OEM or aftermarket ??…sorry but can’t help you anymore.
I understand that, was just hoping someone would have another idea as to why i could keep getting the codes, it its like a programming issue. Thanks anyways,
P0420 & P0430 codes
