Dv8· Life Ruiner
Fast idle valve has problems, its supposed to increae the Idle when the engine is cold, after it warms up it should cut the extra air. either way when you mess with the intake it usually happens. you have to put some sort of restriction on the Fast Idle Pipe or re-tune the Idle. They did away with this system in the RL, goes to show how pointless it was along with all those cooling lines....