When I bought my Blazer the Cats had been cut off. I am sure they were stolen as the job was a total hack. There has always been exhaust leaks and it has sounded terrible. finally last week, the hack job fell apart. Holy crap on a cracker was this thing loud. So I started looking for a replacement from the manifolds back to the muffler. From the muffler flange back was in fine shape. So I found the cat pipe from AutoZone. yea I know but it came with a 5 year warranty and was cheap. 275 with tax to be exact. It was made by Cherry Bomb. At least that is what the sticker said. Anyway, I start soaking the bolts down Friday and Saturday. I planned on replacing the system Saturday after work. The bolts were rusted and good. Took a couple of hours to get them off even with my impact. i then swap the O2 sensors over and begin to put the new system in. Well, to make a long story short, I had to drop the transmission cross-member to get the pipe to fit. Then the studs on the muffler broke. Not sure if anyone has ever tried to drill these things out. They are HARD. Ended up drilling out next to them so I could knock them out with a punch. A new gasket and some grade 8 nuts and bolts and all is quiet. I didn't realize how loud it was until it was quiet. Glad it is done.

 

I had the three bolts at the muffler flange on my 99 ls blazer break due to rust, and the parts left in the flange have a flat pan head that i cannot get anything to lock on to remove them. I've sprayed them down numerous times to break them free but at this point for the price and hassle I think I'm just gonna replace it all from the muffler flange back