2004 Jeep Wrangler Owner's Manual - Page 199

STARTING AND OPERATING 199 It is even more important to look for gasoline without MMT in Canada because MMT can be used at levels higher than allowed in the United States. MMT is prohibited in Federal and California reformulated gasoline. Sulfur In Gasoline If you live in the northeast United States, your vehicle may have been designed to meet California low emission standards with clean burning, low sulfur, California gasoline. Gasoline sold outside of California is permitted to have higher sulfur levels which may affect the performance of the vehicle's catalytic converter. This may cause the "Malfunction Indicator Light" to illuminate. Illumination of this light while operating on high sulfur gasoline does not necessarily mean your emission control system is malfunctioning. The manufacturer recommends that you try a different brand of unleaded gasoline having lower sulfur to determine if the problem is fuel related prior to returning your vehicle to an authorized dealer for service. CAUTION! If the "Malfunction Indicator Light" is flashing, immediate service is required. See "Onboard Diagnostic System" in Section 7 of this manual. Materials Added To Fuel All gasoline sold in the United States is required to contain effective detergent additives. Use of additional detergents or other additives is not needed under normal conditions. 5