Resistance Inspection

WARNING: This page is about a different car, the 2017 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.

Measure the resistance of the spark plug using a ohmmeter as shown in the figure.

Fig 1: Measuring Resistance Of Spark Plug Using Ohmmeter

Courtesy of MAZDA MOTORS CORP.

If not within specification, replace the spark plug.
Spark plug resistance [25°C {77 °F}]

3.0-7.5 kilohms