Hello,
I have a GXP with 132,000 miles on it. I was informed by a GM service mechanic that my mufflers were hollowed out and that a replacement from GM was going to be $1400. He mentioned going to another service shop that was known for fabricating, but I'm not sure I want to do that. Is there a reasonable muffler replacement out there? I did see the Magnaflow but I have no idea if that's any good. Any suggestions? Thanks!