The K&N 67-3109 cat-back exhaust kit is engineered to increase performance, deliver robust sound, and install quickly and easily on certain GM Sierra models. Enjoy excellent quality paired with a simple and clean appearance. The 67-3109 system maintains clearance to critical systems, and typically installs in less than 30 minutes using factory mounting points (no cutting or welding necessary). The system pairs with most aftermarket modifications, including intake systems, throttle control modules, and more. No calibration tuning is required, and complete instructions are included.