Hello Scotty,

You've been a great help to me in fixing my car several times. Thank you so much.

My 2000 Mitsubishi Eclipse has a high idle at start and is revving high and low after driving for 5-10 minutes. I've checked for vaccuum leaks and cleaned the air intake 2-3 times. The problem still persists with the check engine code of P0505. Please help.

Thank you so much.

Best regards,
Arfath Imran.

Often a bad idle speed control actuator does that inside the throttle. Hard to clean, realize it may need replacing on one that old if worn out and it keeps switching up and down.