Installation of the Howell TBI kit makes the air-injection pump obsolete. This will clean up the engine compartment of the Jeep significantly. This also means removing the diverter valves and air tubes that bolt to the factory exhaust manifolds. To do this without causing exhaust leaks, you need to plug the holes in the exhaust manifolds with shorter 9⁄16-18 bolts and copper washers. You can sell your functioning emissions parts to other fullsize Jeep enthusiasts. These parts are hard to find and necessary for emissions compliance in several areas…unless upgrading to the Howell system is a possibility.