2005 Jeep Grand Cherokee Owner's Manual - Page 263

MAINTAINING YOUR VEHICLE 263 To minimize the possibility of catalytic converter damage: • Do not shut off the engine or interrupt the ignition when the transmission is in gear and the vehicle is in motion. • Do not try to start the engine by pushing or towing the vehicle. • Do not idle the engine with any spark plug wires disconnected or removed, such as when diagnostic testing. • Do not idle the engine for prolonged periods during very rough idle or malfunctioning operating conditions. • Do not allow vehicle to run out of fuel. NOTE: Intentional tampering with emissions control systems can result in civil penalties being assessed against you. Crankcase Emission Control System Proper operation of this system depends on freedom from sticking or plugging due to deposits. As vehicle mileage builds up, the PCV valve and passages may accumulate deposits. If a valve is not working properly, replace it with a new valve. DO NOT ATTEMPT TO CLEAN THE OLD PCV VALVE! Check ventilation hose for indication of damage or plugging deposits. Replace if necessary. Fuel Filter A plugged fuel filter can cause hard starting or limit the speed at which a vehicle can be driven. Should an excessive amount of dirt accumulate in the fuel tank, frequent replacement of the fuel filter which is mounted in the fuel tank may be necessary. 7