1. Open the hood of the car.
The spark plugs on a 1999 Nissan Maxima are located on the top of the cylinder head, just beneath the ignition coils.
2. Locate the ignition coils.
The ignition coils are black, cylindrical devices with a rubber boot on the end.
3. Remove the rubber boots from the ignition coils.
Use your hands or a spark plug socket wrench to remove the rubber boots from the ignition coils.
4. Remove the spark plugs.
Use a spark plug socket wrench to remove the spark plugs from the cylinder head.
5. Inspect the spark plugs.
Check the spark plugs for any signs of damage or wear. If the electrodes are worn or damaged, replace the spark plugs.
6. Reinstall the spark plugs.
Install the new spark plugs in the cylinder head. Hand-tighten the spark plugs until they are snug, then use a spark plug wrench to tighten until they are fully seated.
7. Reinstall the rubber boots.
Reinstall the rubber boots on the ignition coils.
8. Close the hood of the car.
You have now successfully replaced the spark plugs in a 1999 Nissan Maxima.
