Improve the performance and fuel economy in any 91/03 Jeep 4.0L Engine with an RT Off-Road Throttle Body. The heart of this kit is a 62mm CNC Machined Aluminum Throttle Body that is designed to provide a smoother, faster, and more dense air charge resulting in increased throttle response, horsepower, and torque. Also included in the kit is a gaskets and mounting hardware. This kit works with both factory and aftermarket air intake systems. NOT CARB Approved.