There are a few different tests for oxygen sensors (also known as lambda sensors), some of which can be run without dedicated tools. The most effective tests tend to be done under normal operating conditions, on a sensor installed on an engine system, though there are some tests which can be done off-vehicle.
Glow plugs are installed on many diesel engines to help with cold starts. They usually fail because of corrosion, overheating, mechanical damage, or metal fatigue, and their failure can cause a variety of problems. The easiest way to test a glow plug is by using a clamp-meter, though digital multimeters can also do the job, and glow-plug testers also work.
General Technologies Corp. introduces the first custom designed milliamp capable automotive current clamp meter, to be used as a stand alone tool which does not require a multimeter to work. With its autorange and high sensitivity, it allows the measurement of AC/DC currents with a resolution down to 1 mA, and a maximum current of …