I recently pusrchased a 04 stang. After a few days it developed a slight rough idle. It has gotten worse and worse, but does not throw a code. I've replaced plugs, air filter, fuel filter, pcv valve, upstream 02 sensors. . I cleaned the throttle body and injectors. I unplugged the maf while it was runnng and idle smoothed out and it ran amazing. So I figured maf was bad got new one installed and same thing. I reset the computer a few times. Nothing is fixing this rough idle any suggestions??? 04 ,72k miles.