Hello I have a 2010 focus ses, I recently made a cold air intake for it, but all my shift points were off and at 80mph my Rpms were at 3500-4000, I had autozone scan it and it said the engine was to lean. What can I do to fix this and my dumb computer?
What is the inside diameter of the mass air section of the tube?. If the inside diameter at the mass air meter is larger than the factory tube, that is your problem. You have two choices if thats your problem, get a tune, or use a factory diameter tube.