lincman29
Member
I have an 06 xlt with a 5.4. I keep getting p0303, p0012, and p0021 codes. I've changed both cam sensors, both vcts, plugs, coils, injector on number 3, and both o2 sensors on bank 1. It idles fine and no diesel noise. Has a light misfire at idle and then dies when you put it in drive or reverse. Struggles around 50 mph when it gets hot, but drives fine when cruise is used. I'm stumped and don't know what else to try. Thought may the cats are gone, but I get no code for them. Looking for any kind of help. Thanks
