Ignition System Checks

WARNING: This page is about a different car, the 2003 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.

Check the spark plugs for the correct gap.
Inspect the spark plugs for excessive deposits that can glow and pre-ignite the air/fuel mixture.
Check the spark plugs for the correct type and the correct heat range.