I've never had a problem with one of these on a Cummins.... but we had 2 CAT's in larger trucks... we'd pull the sensor... actually a TPS at the pedal.... we'd flood it with Brake Clean.... it would flush out of the TPS like mud.... we'd use a 1/3 of a can.... let it dry.. put it back on and it was good for another 2 years or so..... they couldn't keep the dirt out of it...