GMC Sierra Performance Exhaust - Flowmaster American Thunder Cat-Back (2001-2006). A direct-fit cat-back for HD Sierra and Silverado owners who want a deep, assertive sound with proven Flowmaster quality.

This system mounts after the catalytic converter and uses a dual-inlet 50 Series Big Block muffler for a moderate cabin note with a deep, powerful outside tone. A mandrel-bent 3.5 in 409 stainless tailpipe follows factory hangers for straightforward installation and exits behind the right rear wheel, ideal for towing. It finishes with a 4.0 in polished 304 stainless tip and includes a formed aluminum heat shield, plus all parts and instructions. Benefits can include improved throttle response, power, and mileage, and it is backed by Flowmaster’s Lifetime Limited Warranty.

Features

• Fits 2001-2006 (2007 Classic) Silverado/Sierra 2500HD/3500HD; 6.0L or 8.1L; ext/crew; 2WD/4WD; dual-inlet muffler
• Dual-inlet 50 Series Big Block muffler; moderate interior, deep exterior tone
• 3.5 in mandrel-bent 409SS tailpipe; uses factory hangers; exit behind right rear wheel
• 4.0 in polished 304SS tip; includes formed aluminum heat shield and hardware

Have questions or need fitment guidance? Call our team at 512-982-9393 (Austin, TX) or 562-981-6800 (Los Angeles area). We offer installation and customization services at both locations.

Considering multiple items? Contact us for shipping discounts. We install on premises at both locations.

CA Residents: WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov