Diagnostic Aids
WARNING: This page is about a different car, the 2003 GMC Sonoma and 2003 Chevrolet S10 Pickup. However, it is still accessible from the selected car via links, so may be relevant.
Excessive vibration from sources other than the engine could cause DTC P0300 to set. The following are possible sources of vibration: Variable thickness brake rotors, or worn or damaged accessory drive belt. Spray water on the secondary ignition components using a spray bottle. Look and listen for arcing or misfiring.