revs drop no pattern and no not maf

[davemk4]

2001 aum. With no pattern or temp relation my rev drop quite low car judders slighlty. Now maf is new genuine VW not refurb. Boost pipes all good. The usual crap breathers near front all ok or new. I use a k&n so wondered if maf caked in oil? Only 4 months old.?? No error lights no codes pending no drive problems. To clean maf what best quick spray of carb cleaner? Any other suggestions

[jamie16v]

So, in your title you say it`s not the maf, then you ask if it`s caked in oil?...
try unplugging it and see if it makes a difference. as you know k&n are know to use oil as a part of its air cleaning process.. i would use electrical cleaner rather than carb cleaner, but i cant see carb cleaner harming it to be honest.

[dom]

Dirty throttle body?

[jamie16v]

Dirty throttle body?

most likely

[davemk4]

Throttle body was gutted when car was gutted in january. All was cleaned and along with pipe breathers etc. Thing is the fault has no pattern when it does it. Today not once yesterday 4 times

[52GTIPETE]

PCV valve. Will be a hair line split somewhere

[davemk4]

Ill check it later