An engine diagnostic is a test which is performed to learn more about
why an engine is not functioning properly. Engine diagnostics can be
performed by skilled home mechanics with the proper equipment, or a car
can be taken into a mechanic or dealer for diagnosis. The engine
diagnostic is used to gather data which can be utilized in the repair of
the vehicle, and it can also be used during things like emissions
testing, in which a car is checked to confirm that it adheres to
emissions standards for vehicles in its class.
