Spark Plug Test

WARNING: This page is about a different car, the 2008 Mitsubishi Lancer. However, it is still accessible from the selected car via links, so may be relevant.

Remove the spark plug and connect to the ignition coil.

Fig 1: Identifying Spark Plug And Ignition Coil
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Ground the spark plug outer electrode (body), and crank the engine.
Check that there is an electrical discharge between the electrodes at this time.

Fig 2: Identifying Spark Plug Outer Electrode (Body)
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.