What causes fast idle

Hi, fast idle is most often caused by unmetered air getting inside the intake manifold. This could be from an intake manifold gasket leak, manifold leak, air intake hose leak, air box concern, mass air flow concern, throttle body concern or idle air control valve concern. A vacuum leak could be present - check the PCV hose for leaks. Hands on testing is needed. https://repairpal.com/auto-repair-near-me Click the link or call us at 877-913-1554. We'll gladly find you a certified RepairPal shop in your area.