I have a 2003 Honda Element and it is throwing a P2646 code. I found that the majority of posts blame this to the Oil Pressure switch. I replaced it and cleared the code. Drove it around and the code came back and engaged the "limp" mode (2800 rpm limiter). I have also seen posts that say to clean the screen on the V-tec Solinoid (located right next to oil pressure switch). I removed this unit and found no screen to clean. Does anyone have any ideas where I should go from here?