Bought a used Expedition for cheap 120,000 miles and had the CEL on. Code is P0012 bank 1 cam position over retard. I am pretty mechanically inclined I am a aircraft mechanic so I thought I could fix it myself and have a nice Expo for cheap. When I first bought it, there was clicking noise coming from bank 1 and the idle was rough. That made me start with the phaser. While changing the phaser, I noticed the chain guide was broken. So I replaced it as well as the tensioner. I am sure the phaser went on just the same way the old came off. I reset the code and the fuel mileage got better and the noise went away for the most part. After a couple of drives the light came back. So next I changed the VCT solenoid and the cam position sensor. Still a code! Am I missing something! Timing? The noise I hear now comes from the front middle like the oil pump. But if its the oil pump wouldn't you get a code for both sides? Any help would be very appreciated! My local Ford dealership was no help at all.