In a nutshell, I replaced the intake manifold gasket which was leaking at the #2 cylinder. After I replaced the gasket I started the car up and it idled smoothly, after approx. 5 minutes the car began to run rough. I removed the injector wires for the #2 cylinder and it made no difference in the way the engine ran. Did a compression check thinking a piece of the old gasket was sucked into the port and managed to prevent a valve from seating. Compression checked out OK @ 175psi. I then changed the spark plug from another cylinder and still no change, did the same with the coil and injector still no change. I had a friend hook up his OBD II scanner and it showed that #2 and #6 cylinders were not firing. I confirmed this by disconnecting the fuel injectors and there was no change in the running of the engine. Any help regarding this matter would be greatly appreciated. Thank you, Rob.