CAUTION: First, make sure that the engine and ignition are switched off and the vehicle is securely held in place by the parking brake.
ATTENTION! To avoid damaging the spark plug structure, they may only be unscrewed using a special spark plug wrench.
1. Remove the mounting brackets to gain access to the high-voltage cables and spark plugs.
2. Disconnect the cables from the spark plugs. When disconnecting a cable, hold it by the connector and never pull on the cable itself. Mark all cables according to their original positions.
3. Unscrew the spark plugs using a spark plug wrench. The spark plug wrench has a rubber gasket that grips the spark plug and prevents it from falling out after unscrewing. Therefore, before unscrewing, properly place the wrench on the spark plug.
4. On conventional spark plugs, the gap between the electrodes should be checked before installation (the required gap is specified in the chapter "Technical information"). Adjust the gap if necessary.
5. Insert the new spark plugs, one at a time, into the spark plug socket and set them into the opening. Tighten each spark plug by hand a few full turns, then tighten with the wrench to the specified torque. Do not overtighten. The spark plug tightening torque is 20-29 N·m (2-3 kgf·m).
6. Holding the connector, connect each high-voltage cable to the corresponding spark plug by pressing until it clicks into place.
7. Reinstall the mounting brackets.
(Original text on the website: www.NissanBook.ru)