Recently repaired the shifting motor for the transfer case on my 2003 suburban tested and worked great parked overnight and in the morning tried to start it. Ran rough for about 3 seconds and then died will keep running if foot is on gas the the vehicle shakes significantly. Showing codes PO300 and PO101 I put a timing light on it and confirmed that about 5 cylinders were misfiring. I replace the MAF sensor (PO101), Crankshaft postion sensor, and the fuel pump to no avail. Intake manifold gaskets where done 3 years ago. Any suggestions would be appreciated.