97 powerstroke help please
 

my uncles PS is messing up, said he was going down the road and it died, but withbeing a manuel, it started itself back up, i ran the codes,

p0221-throttle switch b circuit range/performance
p0470-exhaust back pressure sensor circuit malfuntion
p0478-exhaust pressure control valve high


it sounds like it has a miss to it also. has since he bought it last year

I would guess you have two different issues. Maybe a sticky or malfunctioning exhaust back pressure valve set the codes previously, and a bad camshaft position sensor can give intermittent trouble without setting a code and cause the engine to quit especially when letting off the throttle. Hopefully someone else will chime in to help support or refute this diagnosis. Good luck.

I would have to agree, I would first find out if it is the old style cps and if is, then ford will replace it with the better newer version under the recall.
If not, then go get one from napa, or International if you have a IH dealer near you. Its about $30 from IH and about $40 from Ford

already been replaced back in january

The miss could be several things, Clear the codes and see what happens after a day or two. The back pressure code is somewhat normal on a older high mile truck, the EBPV sensor tube gets clogged with soot and you get those codes.

The CPS he had replaced or it was done before he got it? I had issues with the newer CPS and went back to the old one... no more issue. Another case of Ford not fixing a Not problem...:argh:

the CPS was changed with one from orielys, didnt fix the problem, so got one from ford, still didnt and ended up being the computer went out. still had the miss then and the back press. code still came back up. comes back on right away as soon as you clear it.

If the code comes back that hard then your EBP sensor is broken/clogged. Get a new one and that code will go away.

Has it done it again? Or just this once?