Bizzare issue's
 

Ok long story short. Did an LS2 swap a few weeks back kept getting p0343, ocassional hard starts etc. Yesterday I swapped to an LS-2 manifold with a 90mm Holley TB. Car started and ran fine. This morning the car would crank for days, but not start. My DTC'c have since changed to a P0341. What is even wierder is that if I plug a cheapie scan tool into the port; the car will start right up. However, if I unplug the scan tool; my oil pressure guage drops and the SES light comes on. Given enough time the car will ultimately die. Does anybody have any ideas?

One thing I would mention is that some of the cam sensor harnesses that went out were defective. They had a couple of wires (I believe the two outside ones) crossed over. I know that this issue caused starting problems and cam sensor DTC's.

Maybe check your earthing too?