5.4 300k miles.just bought it and guy said it needed a coil pack but before i buy cop's want to see what you guys think.
key on engine off codes are p0401 0300 0174
key on engine running codes are ^+ p1000 and 1408
checked all vac lines(good).would a bad egr valve cause the skip or would it just thro the 0108 and 0401 codes?

 

the po401 is probably melted EGR Feedback lines ($20 for 2 packs ) had this happen on mine last week 174 is a lean code so I'd look more for vacuum leaks and clean the MAF Sensor and clean the throttle body change the fuel filter and run some Lucus or techron in the fuel and I think the 300 is a random misfire code.

 

JFC 300k miles? How much did he want for it?

 

So what's 0108 ? You'll need a PCM for that one.

For the 401 and 1408, - Ford Europe has the best info w/diagrams, - look here, -

http://www.fordscorpio.co.uk/egrmonitor.htm

What goes wrong on the 98 is usually the metal body DPFE sensors. They corrode inside..bad, beyond belief (well almost). But yea, check the hoses.

No throttle body worries with the 5fours.

Although your getting the 401, you also have the 1408. That's important for flow hints and because you have the PO300, this leads me to believe the EGR valve is hanging open just a bit. This will cause misfiring. How bad depends upon how much exhaust gases are getting past the valve when it's supposedly shut.

P1000, PO174 are void for now. P1000 is just a monitor thing, stems from a reset/readiness. The 174 can be a result from other DTC's present. But it does suggest to which bank most of your unburnt fuel is going thru.

 

all the vac lines looked fine even the elbow on the back of the intake,,i didnt take the cops off yet,seems to run alittle better once warm but i always get a fuel(timing) ping when i accelerate hard.
also if the cop were bad would they still fire cause at idle its smooth and when i unplug the cops one at a time the engine will die down alittle

 

So, did you read my post yet ?

Ahh, never-mind lol.

 

yes i read it,,ill be pulling the egr off tomorrow,,should i also pull the tb(i know you said no worries)to check to clogged egr passages?

 

Do you think its a problem where the engine jumped time?

 

took the egr valve off and it was closed,applied vacuum and it opened,cleaned it anyway,also took the tb off and inspected the gasket which was good.put it all back together and it still does the same thing,,seems like above 3k rpm is when it startes to skip

 

well not really a skip,just a loss of power and anything past say half throttle it losses power