Once my truck gets up to temperature and I stop or let off the gas peddle the oil pressure gauge drops to zero. Even does it on highway if i let off gas. Seems to be rpm related, at idle if i tap the gas the gauge goes back to normal. Took it in to get checked and of course they could not replicate problem to get a code. Changed oil and filter twice. Switched out oil pressure sensor still happens. No engine noises.
Has anybody had this happen and waht was the fix?