Hi Heres the problem, i did a mass air conversion to my 87 mustang because i put a diff motor in it with a different cam and what not. Any ways it wont idle at all with the mass air plugged in , it opens the iac to 100 % and it sets a min volt code 66 for the mass air. If you un plug the mass it idles fine. What i think is the mass air is no good but not 100 percent sure. The mass air is not brand new so its very possible its bad but i just wanted to see if anyone else had any possibles. The bigger cam wouldlnt cause this probble would it, its only a b cam. Also i read some where that i might have to put a newer style map sensor on it?