What is the effect of a bad air flow meter?

A faulty air flow meter can lead to incorrect readings of the air entering the engine, causing an improper air-fuel mixture. This can result in poor engine performance, reduced fuel efficiency, increased emissions, and potential engine stalling. Additionally, it may trigger the check engine light, indicating that the vehicle needs diagnostic attention. Overall, a malfunctioning air flow meter can significantly affect a vehicle's drivability and longevity.