I’ve been driving all night, my hands wet on the wheel...but I have no idea how fast I’m going. Check out our advice on how to test a transmission speed sensor.

A-The oxygen sensor on your car is in the exhaust manifold close to the spot at which the extension pipe connects to the engine. If the sensor is working properly, there is no need to replace it ...

The oxygen sensor was replaced but the 'check engine' light won't go out. Now what? Which octane fuel is best? AAA's Car Doctor has answers.