Taking off recently I got an "Oil Pressure" warning from my 3400 but since it was less than max (115 psi) at 105 and finally settling in the high 90's I continued the short flight to home plate. Next few times I ran it up it was normal but lately I've noticed that it reads positive pressure in the 30 psi range on deck with the engine off. Could this be an intermittent bad ground or a transducer failure? The unit is a VDO #42,115, 0-150 psi. If it's bad does AFS sell the replacement? (Can't find that exact model anywhere).