How to Replace Spark Plugs in a Nissan Sentra

Most Nissan Sentra models use spark plugs and wires. However, some Sentra models have a CA16DE or CA18DE engine, which utilizes direct ignition where spark plugs are directly connected to the coils. If you are unaware of the type of engine, check the car manual or examine the engine. If there are spark plug wires attached to the engine, you do not have a CA16DE or CA18DE engine.
Difficulty: Moderately Easy
Instructions
Things You'll Need
Screwdriver
Spark plug socket
Socket wrench and extender
Wire brush
Silicone dielectric compound
1

Release the hood and allow the engine to cool.
2

Remove one of the spark plug wires. Grab the wire by the boot at the end of the wire and twist the wire slightly until the wire pops off the plug. Pull the wire off the plug. If you have a CA16DE or CA18DE engine, unscrew the eight screws holding the cover to the engine. This cover is located across the back of the engine, below the intake manifold.
3

Place the socket on the extender and the extender on the wrench. Slide the socket over the spark plug and twist it counter-clockwise to loosen the plug. Remove the socket and pull the plug out of the well. Some Sentra models have deep spark plug wells that require you to pull the plug out with the socket.
4

Clean the spark plug well and wire boot with a wire brush.
5

Apply a light coat of silicone dielectric compound to the threads of the new spark plug and to the inside of the boot.
6

Insert the plug into the well and tighten the spark plug by hand. Turn the plug 1/4 turn with the socket. Tighten any tapered plugs between 14 and 22 foot pounds.
7

Replace the spark plug wire, if used. Turn the wire until it clicks in place.
8

Repeat Steps 2 through 7 for the rest of the spark plugs. Do not remove all the wires at once. If wires are placed on the wrong plug, engine damage may occur. Replace the cover for a CA16DE or CA18DE engine and screw it back into place.