This plug replaces the air intake heater for less restriction in your intake.
The '99.5 and up 7.3L Powerstrokes and the 2001-2005 6.6L Duramax engines are equipped with an Air Intake(Grid) Heater as well as a glowplug circuit. The Air Intake heater is not needed in most cases and was designed for extended idling. This Air Intake heater blocks approximately 20% of the airflow through the intake manifold. By replacing the air intake heater with this plug, you increase airflow, allowing better combustion. This WILL NOT affect cold starts. This fix does NOT cut off heat to the cab.
