Deceleration Fuel Shut Off (DFSO)

During a DFSO event the PCM disables the fuel injectors. A DFSO event occurs during closed throttle, deceleration; similar to exiting a freeway. This strategy improves fuel economy, allows for increased rear heated oxygen sensor (HO2S) concern detection, and allows for misfire profile correction learning. One some vehicles with direct fuel injection, the PCM may also disable the ignition coils. This strategy extends spark plug life during the fuel shutoff events.