2006 Dodge Ram 1500 Pickup Owner's Manual - Page 436

436 MAINTAINING YOUR VEHICLE Also check belt routing to make sure there is no interference between the belts and other engine components. Spark Plugs Spark plugs must fire properly to assure engine performance and emission control. New plugs should be installed at the specified mileage. The entire set should be replaced if there is any malfunction due to a faulty spark plug, malfunctioning spark plugs can damage the catalytic converter. For proper type of replacement spark plugs, refer to the "Vehicle Emission Control Information" label in the engine compartment. Engine Air Cleaner Filter Under normal driving conditions, replace the air filter at the intervals shown on Schedule "A". If, however, you drive the vehicle frequently under dusty or severe conditions, the filter element should be inspected periodically and replaced if necessary at the intervals shown on Schedule "B". WARNING! The air induction system (air cleaner, hoses, etc) can provide a measure of protection in the case of engine backfire. Do not remove the air induction system (air cleaner, hoses, etc) unless such removal is necessary for repair or maintenance. Make sure that no one is near the engine compartment before starting the vehicle with the air induction system (air cleaner, hoses, etc) removed. Failure to do so can result in serious personal injury. Engine Fuel Filter A plugged fuel filter can cause stalling, limit the speed at which a vehicle can be driven or cause hard starting. Should an excessive amount of dirt accumulate in the fuel tank, frequent filter replacement may be necessary.