2007 Nissan 350Z Owner's Manual - Page 252

SPARK PLUGS unexpectedly. 1. Visually inspect each belt for signs of unusual wear, cuts, fraying, oil adhesion or looseness. If the belt is in poor condition or loose, have it replaced or adjusted by a NISSAN dealer. 2. Have the belts checked regularly for condition. REPLACING SPARK PLUGS If replacement is required, see a NISSAN dealer for servicing. WARNING Be sure the engine and ignition switch are off and that the parking brake is engaged securely. CAUTION Be sure to use the correct socket to remove the spark plugs. An incorrect socket can damage the spark plugs. SDI2020 Iridium-tipped spark plugs It is not necessary to replace the iridium-tipped spark plugs as frequently as the conventional type spark plugs since they will last much longer. Follow the maintenance log shown in the "NISSAN Service and Maintenance Guide", but do not service iridium-tipped spark plugs by cleaning or regapping. Always replace spark plugs with recommended or equivalent ones. Maintenance and do-it-yourself 8-17