It has been said on here multiple times that our TB's oil pressure gauge isn't an accurate reading of the oil pressure and that the ecm just calculates certain factors and then shows a calculated guesstimate for oil pressure. Does anyone know why GM did that? Has anyone put an actual oil pressure gauge on these 4.2? Does the normal reading go really low at idle once warm or something? i am trying to wrap my head around why in these modern times that they wouldn't want to display the actual oil pressure of an engine.