[fortcarp]

Most of the online performance shops carry magnaflow for the envoy/trailblazer. Some carry the very expensive borla system, I have never seen a corsa system for these trucks. Be aware that all sites I have researched do not carry systems for the ext models. Not sure if the XL envoy is the longer version or not. Some have tried replacing muffler with flowmaster and the like, but I would need to hear one before I did that to mine. I have a trailblazer ext and just had a shop cut off the ugly resonator and weld me up an SS pipe with nice tip. It did increase the sound some, but not annoying like some performance mufflers.