My new-to-me 2002 DeVille threw a P0410 code before I got it but it went away on its own, according to the car lot selling it. Now it threw a P0420 code. I had a mechanic check it out and he said the code was thrown because the cat needs to be replaced.

So, three questions:

1) Is the cat replacement on the '02 DeVille a DIY yourself project, given the rest of the exhaust is stock and I can find a direct replacement;
2) How much should I expect to pay for a direct replacement cat ($154? $800?); and
3) Once it's replaced, does anything else need to be done other than clearing out the service engine code (e.g. reset any other computer components or anything)?

Thanks, y'alls.

P.S. I am hoping the cat simply needs to be replaced due to age (~10 years old and 130,000 miles) and not because of another underlying issue.

 

the cat can be a DIY if you have the equipment.i.e. weleder, bolts, etc. most exhaust shops dont charge all that much to install them. The costs of the cat can range from $120 to $300. You can get a replacement from the exhaust shop they can give you info on the types you may want. if you dont have strict emmisions you can use a high flow cat which is better flowing and cost just as much as a replacement. As for the codes poping up once the new cat is installed all you need to do is clear codes and youll be fine.