Car diagnostic tests scan a car’s components and integrated systems for errors or malfunctions before they become dangerous. These tests leverage computerization to keep your car in optimal working ...

Gear-obsessed editors choose every product we review. We may earn commission if you buy from a link. Why Trust Us? The check engine light by its nature is vague, just a general indication that ...

Almost all cars made after 1996 have an OBD2 diagnostic port for plugging into and reading trouble codes when a “check engine” light comes on. But some vehicles, particularly German ones made after ...