With the unit hooked up to the 12-volt battery in the car and the car up to normal operating temperature, we measured a 7.5-percent CO reading, indicating that the engine was idling at a very rich ...

We show how easy it is to install FAST's Air Fuel Ratio meter on an Edelbrock 600-cfm and Holley 600 Single Pump 4160C carburetor.

The content of the engine's exhaust can be read to indicate what the air/fuel mixture is at any rpm or load and how efficiently the engine is burning the fuel.

If you're having trouble getting your car to start, especially on a very cold day, the engine may be flooded. Here's how to tell, and how to fix it.

The engine’s computer automatically compensated for the restricted airflow by reducing fuel use to maintain the right air-fuel ratio. We expect similar results after any air-filter change.

A misfire means that a cylinder in your engine isn’t producing the power it should because the air-fuel mixture in it didn’t properly ignite and burn.