Possible Cause

DTC P0300 set with P0301, P0302, P0303 or P0304 indicates random misfire. To determine cause of misfire, check the following:

• Low compression. See ENGINE COMPRESSION under PRELIMINARY INSPECTION & ADJUSTMENTS in BASIC DIAGNOSTIC PROCEDURES article.
• Poor fuel quality.
• VTEC system malfunction. See appropriate VALVE TRAIN article in ENGINES.
• Correct valve clearance. See appropriate procedure under VALVE CLEARANCE in ON-VEHICLE ADJUSTMENTS article.