That is an interesting question .. not one ive ever looked at before .
For vacum lines ie splits then you have additional air entering the intake after the maf so it would show on a tester useing the addaption figures...
Maf readings may also be low .
If too much air then you WILL get a fault code as the car can only addapt so far.
You would see that the car is haveing to richen the mixture to maintain Lambda .
The car would probably still run ok as the car can compensate for the air leak ( it increases injector duration basically ) .
For an AOS though .. hmm .. the main part is oil getting past the AOS and into the intake which in turns get burnt and causes smokeing .
In theory you would get something on the addaption figures but i dont see how you could nail it down to an AOS .. it could be many things and without any smokeing its not something i would jump at.
If i thought an AOS was in the early stages of failing then i would remove the throttle houseing and see how much oil was in the intake system .
There is a problem with this method though .. there WILL be oil in the intake .. its normal .. so the decision is how much oil is normal or a problem.
I have seen what was an AOS by this method before but ive seen many intake systems so know roughly what is normal .. even so i could get caught out so its not a method i would advise.
Rule of thumb .. if its smokeing from both banks when warm then an AOS is the most obvious and you would then check as above if needed.
Your reading of 24 .. is that maf kg/hr ?
To test the maf ..
Car running and warm .. a/c off and its about 16kg/hr .. a/c on and about 18kg/hr.
Ign on but not running and look at the maf voltage on the tester 0.9-1.1 volts and its ok .. well .. it shows its not contaminated but imho it doesnt prove the maf is ok .
On cold start it will be higher .. revs are higher
Thats just my opinion though and im no expert .. if anyone has more info then i also would love to hear about it .
