It is indeed.

In my opinion I use OE parts. Have seen to many A/M cats fail with in a few years. I have found that their cheaper for a reason. Gm has Heat riser penetrate that is the best I've found for rust. Been using it for almost 40 years. works best the longer you let is sit. As for pulling the rear cat. It'* straight forward. Getting at some of the bolts can be difficult but it'* just nuts and bolts. Best to you