a week ago my truck started running very rough when under load, it sort of kicks and shakes almost exactly as if it has water in the motor(happened to me before, but aint the cause this time around, ive ran several tanks through it) It will run almost fine until it gets fully warmed up then it gets to shaking real bad when i give it gas. it shakes slightly at idle too. ive ruled out the tranny by it will shake at idle in p,d,n, etc and dont shake none when coasting. Autozone pulled three codes for me: P0401 (EGR system fault, ECM has detected to little flow on the EGRsystem) P0301 (Cylinder one misfire) P1151 (lack of O2 bank 2, ECM could not adjust fuel trim because of a lean or rich condition)

i aint really worried about the first code i dont care for the EGR system one bit and wish it came without one however the second one im worried over. the third i would think would only mean i need to get a new o2 sensor, its got two brand new cats that function fully

im hoping changing the plugs coil packs and wires might solve the misfire and possbily the other two codes. anybody had a similar problem/codes, any suggestions or resolutions?? one other question, ive heard so much on this site about the infamous plugs breaking off, im pretty sure a 2000 4.6L 2valve would be in that group of motors with that plug problem?

 

No, the breaking problem is only the 04-mid 08 5.4 3 valve engines. YOUR engine is the one that blows them out if you don't torque them in enough. 28 ft/lb, do NOT use antiseize. Use only Motorcraft plugs.

You NEED to fix the EGR fault first, along with the misfire. Don't care if you don't like EGR, it's there and has to be working properly or it will never run right. Pull your throttle body and clean it, and I bet you find the EGR passages in it are all plugged up with crap.

 

I am sort of having the same issue. I own a 2005 F150 4.6L. I have a check engine light and lots of codes but my mechanic narrowed it down to an EGR problem (P0401). I have tried everything like you have. My truck has a rough idle with a coughing sound coming from the exhaust. The truck shakes when accelerating and when I get to about 50-55 MPH it seems to loose power. Today while test driving it after cleaning throttle body and plenum, the check engine light even started flashing. It will sometimes stall when decelerating. I also notice white smoke (exhaust gas leak) coming from under the passenger side of the engine which seemed to be from right above the first cat on that side. I have replaced the EGR Valve, MAF, throttle body censor, cleaned throttle body and plenum (made sure to get the EGR port clean), replaced plugs. My mechanics only other guess is to take off the intake and clean the egr ports in there and then replace the gasket since i have signs of a bad gasket. That bad gasket could also be ruining my coils. I'm kind of stuck. Any thoughts anyone?