Not sure which 1999 GMC Sierra Performance Mufflers are right for you? We have over 976 customer reviews, with an average rating of 4.5, to help you find exactly what you're looking for. Here's what some of our customers have said:
"Good quality muffler. Loud but not loud enough to get pulled over. Love the sound once I reach 2,000 rpm." —Rafael M from Melrose Park, IL bought a Flowmaster Super 44 Series Mufflers for a 1999 GMC Sierra.