2000 Ford Crown Victoria

My car shakes and wants to die in drive while my foot is on the brake. I was told it had a vaccum leak. I put a new pvc valve and it made it worse. It revs itself up and kind of jerks forward when in park and running, also while in drive and stopped. It also has a hard time taking off. The check ingine light is on and sometimes blinks while going up hill and things like that, the code says it is spark plugs, vaccum leak, bad fuel injector, or high or low fuel pressure. I am not sure what is going on and neither is my mechanic. Is it possible the pvc valve was the wrong one or is there another problem?