Hello guys,
I have mustang 2015 within 2018 intake manifold,kooks headers and airaid cold air intake the proplem is when the car runs then shift to netural the RPM goes up and down (RPM not constant) it seems there is excess air going to the engine so have you ever seen or heared about proplem like this ? I really need your help guys because the tuner and the repair shop do not know why is this proplem happening