I have a 2003 Avalanche with the 5.3 that has had the catalytic convertors stolen off of it. A buddy has a 2005 Avalanche with the 5.3 that he is parting out. Will the catalytic convertor fit on mine? I see where Rock Auto has them listed as a different part number but from what I can tell looking underneath they appear to be the same. I don't want to hassle with removing the one from his if its not going to fit. Thanks for any help.

 

Personally I think they should be interchangeable, but that is just my opinion. Unless there was a significant engine redesign between 2003 and 2005 that would change the expected back pressure and flow of the exhaust system, which I doubt, there is no reason they would be different. And for you, as long as it is cleaning up things so you pass emissions inspection is the key thing, assuming you live somewhere where that is an issue.