The GMC division of General Motors introduced a two- and four-door line of sport utility vehicles to consumers in 1992. Prior to this lineup change, the GMC Jimmy was the large truck that shared similarities with Chevrolet's Blazer. The Yukon, which now shares the chassis and engine platform with the Chevrolet Tahoe, features a shorter wheelbase than the Chevrolet Suburban and GMC Yukon XL vehicles. For the 2003 model year, the Yukon came with two engine options: a 4.8L V8 or a 5.3L V8. Keeping this truck tuned and serviced properly is a routine procedure you can perform at home.
Disconnect the Yukon's battery by removing the negative connection.
Remove the spark plug wires, individually, from their respective plugs by pulling on the boot. Use the plug wire boot puller for best results.
Inspect the spark plugs to determine whether or not you should replace. Note spark plugs with signs of corrosion, overheating marks, damage, wetness or any other physical wear. Replacing these plugs is far more effective than trying to clean and repair them.
Remove the necessary plugs with a wrench.
Remove frayed or damaged wires by pulling on the boot from the ignition coil.
Replace plugs and wires that were removed with the new parts. Install the new plugs and wires by hand for best results. Reattach the corresponding wires to the correct plugs.
Loosen the bolts that hold the old air filter box in place with the rest of the intake system. Replace the air filter in the Yukon about once a year, unless driving conditions become harsher or more frequent.
Remove the casing of the air filter to access the main compartment of the Yukon's air system.
Remove the air filter from its position slowly to minimize spilling of any debris.
Lower the new air filter into place, ensuring that the filter lines up with the intake system's main tube.
Tighten the bolts to secure the filter's position.
Remove the cap and sealer of the fuel injector cleaner. Add fuel injector cleaner to your engine for maximum performance every 4,000 to 6,000 miles. Wait until your gas tank is below a quarter tank before proceeding with this action for best results.
Add half of the fuel injector cleaner to the gas tank of the Yukon.
Fill the gas tank halfway with fuel. The 2003 Yukon holds approximately 26 gallons of gasoline. Use that as a reference for administering fuel.
Empty the rest of the fuel injector cleaner into the gas tank for mixture.
Fill the rest of the Yukon's fuel tank with fuel.
