i dont know what is worng we have checked for vacume leaks and the computer gave us the "air mixture lean malfucntion", my car idles at 450-550 rpm and is very rough has anyone had this before?

 

Mine was just doing that - it ended up being a crack in the tube that goes from the airbox to the intake manifold. It was cracked right at the ISR. I temporarily fixed it with some duct tape, and I will be performing the good ol' ISR mod this aftenoon.

 

thanks for the reply i know its not that becaus i tested for vacume leaks all around there

 

Check ALL vacuum hoses to include ADD all the way to the differential (if you have ADD). An unlit propane torch is a good way to check. THe idle will go up if you have a leak.

 

Agreed. I had the same problem and it was a crack in the EGR valve that I could not see. Vacuum leak.