egr valve insufficient flow

[mel15]

i just replaced spark plugs and egr valve on my 2000 ford expedition. still skipping and diagnostics says it's still the egr valve! what's going on? what do i need to check next?

[carlos80]

Engine and mileage? Get codes pulled Autozone can do this and post them up. Does the "skipping" get worse when the vehicle is in gear but not moving? How about fuel filter how long since you've replaced that? Any injector flush through tank?

[mel15]

thanks for the reply carlos80. mileage is 114,000. 4.6L v8. i did take it advance auto and they told me the code is still showing egr insufficient flow just as it was before replacing egr. fuel filter was replaced not quite 1 yr. ago. i have put inj. cleaner in at different times, not lately. any suggestions?

[way2old]

If it is a P0401, replace the DPFE sensor. Alsio it might be a good idea to remove the EGR again and make sure the 2 ports under it are clean and not plugged with carbon.

[carlos80]

Way2old hit it right on the head. The 4.6 has this problem alot, I usually just remove the throttle body and clean up the EGR ports with a small file and brake cleaner.

[carlos80]

I usually test for this by applying vacumm to the port on top of the EGR valve while at idle, park, and A/C off. You can do this with a small hand vac pump or just attach a small vac line that fits it snug and suck on it, the more vacumm you apply the more the engine should stumble, if it doesn't stumble and valve(port) holds vacumm then you probably do have carbon clogged ports.