| 1972-1978 4.2L(258CID) Jeep vehicles equipped with carburetion system, Exhaust Gas Recirculation (EGR), Positive Crankcase Ventilation (PCV) and Evaporative Emission System (EVP).
1979-1989 4.2L (258 CID) Jeep vehicles equipped with carburetion system, EGR, PCV, EVP, Air Injection-valve, Oxygen Sensor, and three-way plus Oxidation Catalytic Converter (TWC + OC).
1990 4.2L (258 CID)_ Jeep Wrangler equipped with carburetion system, EGR, TWC + OC, Pulsed Secondary Air, and Oxygen Sensor. | Modifications to the OEM system includes Idle Speed Throttle Plates and Valves, Choke and Accelerator Pump, Anti-Backfire and Decel Valves, Air-Cleaner, Heat-Riser, Delay and Check Valves, Ignition Distributor, Mechanical Vacuum Advance, Pulse Air Injection, Solenoids, Vacuum Switch, Check Valve, PCV Valve and Solenoid, OEM Computer and Electromotive Replacement includes Idle Air Control Motor (IAC), Throttle Position Sensor and Mass Air Flow (MAF), Fuel Shut-Off by Computer, Air-Duct to Air-Cleaner, Distributorless Ignition System (DIS), PCV valve and TEC II Computer. |
