so I have come to notice that after I drive my truck for over an hour straight like on a freeway without stopping I'll come to a stop and when my rpms go below 1000 my oil pressure gauge will drop a little bit and start flickering like crazy. It goes back to normal once I hit the gas. Any suggestions of what could cause this?

 

The sensor (which is a pressure switch , these are dummy gauges) is going bad .

 

Ya I have the same problem sometimes. My speedo did it a while back too. Started shooting to 45mph what I was stopped. then hit the gas and it went back to the actual speed...

 

My mechanic checked mine out while he was under the hood. Said it was the switch. The pressure and oil pump were fine. I think there is a TSB on this.