I have a 95 elantra with a 91 gallant vr4 turbo motor in it, I was getting on it then the car backfired after that its been all down hill ever since. The car will run like crap with the mass air flow plugged in but with it unplugged it will idle fine but only rev to about 2500, if I plug the maf in and put my hand over it the car will rev fine but my couplers are not swelling at all like its not make any boost. check to see if the turbo was locked and it spins fine plus vacuum lines are fine, does anyone know what's going on?