Can You Test A Spark Plug With A Multimeter

When spark plugs are new, the resistance value is between 500 and 3000 ohms. As the plug ages, values below 5000 ohms are acceptable. But once the plug's resistance value exceeds 5000 ohms, the plug should be replaced. If a spark plug falls off a workbench or is dropped, it's possible for the carbon resistor to break.

Can you test a spark plug without a spark plug tester?

The check is very simple! If you remove a particular spark plug wire and the speed of the car's engine drops or it starts running a little bit rough, that's a sign of a good spark plug.