i have a 1997 pontiac with a 2.2 engine.at idle when fully warmed up the oil ligth goes on.as soon as you step on the gas the ligth goes out.there is no noise from the engine at idle when the ligth is on. had the oil pump replaced but still have same problem.had mechanic put a mechanical guage on it but he admited his guege was not very good.at 3000 rpm i have 55 psi of pressure.would an after market electrical gauge help?