2001 ws6 p0420
Thread Starter
Staging Lane
Joined: Sep 2016
Posts: 91
Likes: 2
From: Minneapolis
2001 ws6 p0420 Hey gearheads,
I have a P0420 on my 2001 WS6. I hooked up my new scanner and the downstream readings on my O2 sensor are stable while the upstream readings are moving up and down which seems to be expected.
Ive hears the cats can go bad. Mileage is 105k. Any thoughts or suggestions? Or any posts i should refer to? When searching the posts i found limited helpful information for my situation so far - im guessing some good posts could be buried?
I have a P0420 on my 2001 WS6. I hooked up my new scanner and the downstream readings on my O2 sensor are stable while the upstream readings are moving up and down which seems to be expected.
Ive hears the cats can go bad. Mileage is 105k. Any thoughts or suggestions? Or any posts i should refer to? When searching the posts i found limited helpful information for my situation so far - im guessing some good posts could be buried?
Joined: Nov 2001
Posts: 34,647
Likes: 2,573
From: Schiller Park, ILL Member: #317
Yes, the 2000-02 cats on V8 4th gens are known to fail. GM issued a TSB for this. The coatings wear off the substrate and the cat becomes nothing more than a pass-thru with limited oxygen storage capacity therefore an increase in tail pipe emissions. There is nothing to worry about as long as you don't have to pass an emissions test. If you do, you can either replace the cat(s) or disable the SES light for the P0420 & P0430 DTCs via a custom tune or O2 simulators.
Sometimes the substrate will break apart or melt and become clogged, but that's an entirely separate issue and would come with several obvious driveability concerns. If there are no issues other than the code, then it's likely a simple case of the known issue regarding coatings wearing off the substrate. No action is required unless you have an e-test to pass.
I've written extensive and detailed posts about this topic over the years, several of them. Perhaps the site search feature is not picking them up for some reason, but I am 100% certain they are there. In any event, what I wrote above is really the simple bottom line.
Sometimes the substrate will break apart or melt and become clogged, but that's an entirely separate issue and would come with several obvious driveability concerns. If there are no issues other than the code, then it's likely a simple case of the known issue regarding coatings wearing off the substrate. No action is required unless you have an e-test to pass.
I've written extensive and detailed posts about this topic over the years, several of them. Perhaps the site search feature is not picking them up for some reason, but I am 100% certain they are there. In any event, what I wrote above is really the simple bottom line.
Thread Starter
Staging Lane
Joined: Sep 2016
Posts: 91
Likes: 2
From: Minneapolis
Yes, the 2000-02 cats on V8 4th gens are known to fail. GM issued a TSB for this. The coatings wear off the substrate and the cat becomes nothing more than a pass-thru with limited oxygen storage capacity therefore an increase in tail pipe emissions. There is nothing to worry about as long as you don't have to pass an emissions test. If you do, you can either replace the cat(s) or disable the SES light for the P0420 & P0430 DTCs via a custom tune or O2 simulators.
Sometimes the substrate will break apart or melt and become clogged, but that's an entirely separate issue and would come with several obvious driveability concerns. If there are no issues other than the code, then it's likely a simple case of the known issue regarding coatings wearing off the substrate. No action is required unless you have an e-test to pass.
I've written extensive and detailed posts about this topic over the years, several of them. Perhaps the site search feature is not picking them up for some reason, but I am 100% certain they are there. In any event, what I wrote above is really the simple bottom line.
Sometimes the substrate will break apart or melt and become clogged, but that's an entirely separate issue and would come with several obvious driveability concerns. If there are no issues other than the code, then it's likely a simple case of the known issue regarding coatings wearing off the substrate. No action is required unless you have an e-test to pass.
I've written extensive and detailed posts about this topic over the years, several of them. Perhaps the site search feature is not picking them up for some reason, but I am 100% certain they are there. In any event, what I wrote above is really the simple bottom line.
