[86_mustang]

i purchased a pro m mass air harness and installed it its a a four wire harness i also changed the computer to a a9l computer once i installed evrything the car turned on but it will idle like it had a cam and i cant figuire out whats wrong i changed the map sensor to a bap sensor from a newer mustang and it still has the problem any help ??

[EagleAutosports]

How does it run otherwise? A rough idle can be caused by many things so tell us more about it. Does it have the rough idle all the time, only when it's cold, after it warms up? Does it surge? Does it run normal when at speed?

[86_mustang]

the mustang is not drivable becuase its shuts down everytime i put it in gear because it idles low...

[86_mustang]

the problem started when i connected the harness and changed the computer ... i instaled a a9l computer a mass sensor from a 91 mustang and a bap sensor from 90 mustang

[89coupe]

Auto or 5 speed setup?

[86_mustang]

its a 5 speed setup