Check the Vehicle Emissions Control Information ( VECI ) decal
located in the front of your engine compartment ( it will show the
type of spark plugs to use and the spark plug gap )
.054
The spark plug gap for a 1999 Honda Civic LX is 0.044. You can use a plug gap tester to check the proper gap. You should always check the gap on all spark plugs prior to replacing the spark plugs.
The spark plug gap for a 1999 Mazda 626 with a 2.5L V6 engine depends on the type of spark plug. Platinum plugs have a gap of .032 inches, while iridium plugs have a gap of .044 inches. However spark plugs come pre-gapped and do not need any adjustments.
The spark plug gap for a 1999 H-D (Harley Davidson) is .032 to .036. The actual gap depends on the brand of spark plugs.
.040 inch
The 1999 Kia spark plug gap setting is .035. Most spark plugs will be pre-gapped by the spark plug manufacturer.
.054"
A person must leave the right size gap for the spark plugs when changing them. The 1999 Chevy Suburban has a spark plug gap of .060 inches.
DO NOT gap the plugs. They are factory set at .054. If you DO gap them, you will ruin the platinum coating and they will be NO GOOD!
When changing the spark plugs on any vehicle, the person must leave the right gap size. The 1999 Harley Softail has a spark plug gap size of .040 inches.
.032
The spark plug gap on a 1999 VW Passat should be set at .032 inches. New spark plugs are preset, however, and should need no adjustments.