thanks . I beleive it was over filled by a quart.. Maybe it messed up my oil pump with the oil getting frothy from overfilling... What other 'basics' are there for me to check besides the one you listed? What scan tool would you recommend to buy? I do not have good trouble shooting knowledge on engines... When the truck is in drive it has jerky acceleration with weak power. Pushing harder on gas makes it rev too high and not a smooth acceleration what so ever.smj999smj wrote:The crankshaft position sensor, which is located on the top/left of the transmission bellhousing, will not affect drivability on VG-series engines; it is for ECM monitoring, only. As to why you have low power, is hard to say. You don't mention how much you overfilled it. If it was a quart or less, the overfill may not have anything to do with the current lack of power, even if the timing of the issue in regards to the overfill would suggest otherwise. Often I see crank position sensor codes trigger on these engine when the distributor is starting to fail. Sometimes you just need to check your basics: fuel pressure within specs, condition of secondary ignition parts, exhaust restriction, etc.