Flowmaster introduces our Flow FX Extreme stainless steel cat-back exhaust system for the 2003-2024 Toyota 4Runner with the 4.0-liter engine. This system uses a Flow FX series muffler for an aggressive sound level and increased performance. 3.00-inch mandrel bent 409 stainless steel tubing allows for maximum exhaust flow and durability. The system has a turndown style, dump exit right after the muffler to eliminate the over-axle tailpipe. This elimination of the tailpipe helps improve ground clearance and departure angle when you are driving in more extreme off-road situations. This system produced max dyno gains of 4 hp and 5 lb-ft at the rear wheels. All of the necessary hardware is included, and factory-mounting locations are used for an easy installation. Backed by Flowmaster's Lifetime Limited Warranty.