Flowmaster FlowFX Cat-Back Exhaust System, Dual Exit, Rear Exit

A cat-back exhaust swaps the factory pipes, muffler and tips behind the catalytic converter for less restrictive tubing. This is Flowmaster's FlowFX system in a dual rear-exit layout, with both tailpipes exiting behind the rear wheels.

why this one — Cheapest cat-back here at $949.95 and the only one claiming a double-digit gain at both ends, +21 hp and +26 lb-ft. That figure is Flowmaster's own published number rather than an independent test, and it was found on a reseller listing instead of Flowmaster's page, so read it as a best case and not what your truck will make.