What is a maf sensor and where to in 2000 Toyota Echo?

A Mass Air Flow (MAF) sensor measures the amount of air entering the engine to help determine the correct fuel-to-air ratio for optimal combustion. In a 2000 Toyota Echo, the MAF sensor is typically located in the intake air duct, between the air filter and the throttle body. Proper functioning of the MAF sensor is crucial for engine performance and efficiency. If it's faulty, it can lead to poor fuel economy and engine performance issues.