EGR/intake/other diagnostics--is this the right train of thought?

[megaladon6]

i replaced the EGR valve today for a couple of reasons
--strange MAF readings ie more air than specified by approx 250mg/stroke
--when using "adaptaion" in VCDS the value stays at 85.5% no matter what.
--it was leaking oil onto the intake
after the replacement i can now adjust the EGR from 85% to 50%
the vacuum at the EGR is 20in/h20 at idle and drops to 0 at WOT.

i cleaned the intake in may, it already has a good layer of gunk on it, somewhere between 1/16 and 1/8in.

my diag/guess is that the EGR valve has been stuck open all the time. this is why my intake is already gunked.
does this sound right? (my oil level has gone down by approx 1qt over 5000mi, so i assume it's just the CCV and not the turbo)

ALSO
since i bought the car in may, it's had low power under 2400RPMs. nothing extreme, but noticeable. i assumed it was the intake but it didn't change after cleaning. once i reach 2400 the power comes up very noticeably. i can hear the turbo spool as soon as i accelerate and well before 2400. i have also watched the boost numbers in VCDS and specified/actual are always very close.
could the EGR have any effect on this?/what could?
the car also smokes quite a bit on startups under 50*F. i replaced the glow plugs and harness, FWIW.

any and all help is appreciated!
thanks
nick

 

[UFO]

Correct that your EGR valve was bad, but it was stuck shut -- that's why the duty was jammed wide open and your MAF signal was still too high.

The intake gunk was from the EGR working correctly until it failed. I have no explanation for your oil consumption, but 1 quart in 5k miles is not too bad and probably the CCV as you mentioned.

 

[VWBeamer]

The good news is if was stuck shut, now that it's open you should see a litle bump in MPGs

 

[megaladon6]

Correct that your EGR valve was bad, but it was stuck shut -- that's why the duty was jammed wide open and your MAF signal was still too high.

so the EGR value is based on measured flow and not the N18 duty cycle? (as commanded by the ECU)
also, if the EGR was stuck shut, why do i have so much gunk built up in such a short period?
don't know what difference this makes but...i just remembered that soon after the intake cleaning, the CEL came on with an EGR insufficient flow code. which of course reinforces the valve being shut, but i still come back to "why all the gunk"

The good news is if was stuck shut, now that it's open you should see a litle bump in MPGs

god i hope so! that's one of the annoying things about this car, i'm only getting 40mpg
thanks for the help