Gasmonkey

Hi, I have a 2011 Audi A4 b8 2.0 tdi, when changing the air filter I noticed there was a sensor in the bottom of the filter housing, can anyone tell me what it is and what it does please?
thanks

Li7

A mass (air) flow sensor (MAF) is a sensor used to determine the mass flow rate of air entering a fuel-injected internal combustion engine.

Gasmonkey

its not the maf sensor as the sensor I am talking about is in the bottom of the air filter housing u can only see it wen u take the air filter out, any ideas?

SMac770

Only reference I find is a N335 intake air switch-over valve. Apparently, it has a vacuum line attached to it?

Gasmonkey

Yes it has a vacuum line connected and a plug onto the bottom of it that comes through the bottom of the air filter housing, any idea what this does?i was going to fit an induction kit but this was there so don’t want to take the housing out and remove this without knowing what it does

thanks

SMac770

I only see it in reference to the 3.2L V6, the V8, and that the TT with CDMA engine has one. It seems to have something to do with managing air turbulence and/or intake runner length.
I would find it unlikely that others in the GB wouldn't be aware of this item, as TDI is vastly more common there. No input over at audi-sport.net (what I consider to be the GB Audi forums)?
If you're getting a new intake, I would hope they would be aware of this item and how to handle it.