Have a 2003 Sebring LX 2.4 coupe just did a valve cover gasket now I have a P0303 code. Motor idles rough (to the point of dying) hearing vacuum noise, have sprayed the engine with starting fluid and the engine does not change. I have since replaced coils, plugs, wires, cleaned intake and nothing calms the engine. Disconnected the fuel injectors one at a time....1 and 4 stalls the engine while 2 and 3 don't affect it at all.

Really in need of help

 

Go back and check all your work. Especially the wiring to spark plugs 2 and 3. Make sure those two aren't mixed up. Check for spark at those plugs. Also check very carefully for a vacuum leak. Take a length of tubing and hold one end near your ear while you search the other end around the engine.