98 12valve where is it located. I just bought a second truck and the oil gauge drops then comes back up .Shows good pressure other than that. Im going to try a new sender and see if that works

 

its on the drivers side of the block, behind the p.s. pump, look through the fender well and you will see it

 

Is the Oil Pressure gauge governed by the PCM in a truck built 11/97 (98 model) ??

If so, can the Dealer "TWEAK" the range (with a code reader or whatever it's called) so the Oil pressure can be kept from constantly dropping to zero at idle ?