I've got an '09 370z Touring with a crack in one (or possibly both) cats. The crack in the left cat was welded by a small shop two years ago, but apparently it's starting to leak. Dealership says both have cracks, they're probably full of it. Dealership wants $2,500 to replace both, small shop guessed $3,500, but will get back to me with a more exact quote. I'm at 120k miles, I'm in SoCal, and have no desire to get HFCs or anything like that.
My questions are:
- Even if there's only one bad one, should I just replace both anyway since I'm at 120k miles?
- Is there any good reason not to just buy a pair from the Parts for Sale forum and just pay labor?