As my car has been a right PITA for the last week or two with overboost faults, I swapped these two valves over at lunchtime.

Doing this seemed to change the driving profile of the car - there was a little less grunt low down in the revs but it seemed to pull ok from about 2.5k up (limited testing on site at lunch time when the MOD police weren't watching me go up a hill in 2nd!).

So I decided leave then swapped over and drive home. It still had a limp home occurance, but was certainly better than the 4-6 limps I had in the morning.

My question is, that as I have blocked off the EGR, the valve on the left is pointless anyway, but do they both have the same profile? I assume they must be different as VAG would not make one with a black top and one with a white top if they were the same internal spec?

They are both changeover valves but are different parts, but I couldn't tell you what the difference is. Given that these are driven directly by the ECU, I wouldn't want to swap them without measure the coil resistance first.

From memory...

The N18 is 1J0 906 627 or 1K0 906 627 D

The N75 is 1J0 906 627 A or 1K0 906 627 E

Cheers - I'll check the resistances tomorrow and maybe swap them back. I am thinking that maybe I need a replacement n75, but I don't like to take the Skoda Dealership approach - change parts till it works!