Some folks throw them away and plug the holes. The "flap" routes the hot exhaust back upward to heat up the intake manifold for better combustion. Once the engine is hot it makes no difference...... just my penny version!
Wally, I've not seen one from the factory on our pickups that did not have one at least in the beginning......but I could be wrong!
Last edited by Achipmunk; 08/30/2017 3:47 AM.
