The Matiz is equipped with one spark plug per cylinder, for a total of 3 spark plugs on 3-cylinder models and 4 plugs on 4-cylinder models. You should change the spark plugs at least once per year, or more frequently if necessary. Bad spark plugs can cause engine misfires, poor fuel economy and poor emissions. The plugs can be changed in under 30 minutes with a ratchet and spark plug socket.
Pull the bonnet release lever on the lower left hand side of the driver's area. Pull up on the exterior bonnet latch release and raise the bonnet. Support the bonnet with the supplied prop.
Locate the spark plug boots at the front of the engine near the exhaust manifold. Allow the engine to cool down before attempting to remove the spark plugs.
Pull the spark plug boot outward to reveal the spark plug. Use a ratchet with a spark plug socket to remove the spark plug from the engine.
Use a gap tool to check and set the gap on the new spark plugs if they haven't been pre-gapped. The recommended gap is 0.043 inches. Lower the spark plug into the recess on the engine and carefully thread it by hand.
Use a torque wrench to tighten the spark plug to 15 pound-feet. Place the boot over the spark plug and push firmly on it until it snaps on. Repeat the procedure for the other spark plugs. Close the bonnet when finished.
Never over-tighten the spark plugs. Doing so may destroy the threads along the block wall or the spark plug itself. Always replace the spark plugs one at a time, to avoid crossing up the spark plug wires.