Shop MagnaFlow Performance Exhaust Systems for the 2005 Pontiac GTO, including cat-back exhaust systems for select engines, trims, and configurations. Engineered to produce MagnaFlow's deep signature exhaust sound, these systems feature premium materials and easy direct-fit installation. 2005 Pontiac GTO exhaust options include 2.5-inch and 3-inch main piping diameters; polished exhaust tip finishes; dual split rear exit styles. Use Shop by Vehicle to find the system for your GTO.