Im having an issue with the oil pressure gauge (maybe) At an idle it's where it should be, but when I give it gas (driving normal) it goes up then down and then back up. At a steady speed, any speed, it again is where it should be. Im not sure about the hesitation or whatever you want to call it. Checked oil and its good. Im running sythetic 10w30 in it. Could it be the sending unit or maybe the oil filter may not be flowing enough? Also I've had the truck for about a year and it just started doing this a couple weeks ago. Any input would be a great help!