I searched for about an hour and give up. I had to replace the rubber duct that goes between the turbo inlet and the MAF because the rubber cracked where the clamp was. At the intersection where the PCV hose joins the duct, there is a sensor with an electrical connector. Any idea what it is and what happens if it fails? I disconnected it to see if the monitoring system might give me a clue but I didn't get any codes, maybe because I didn't drive it long enough.

 

As an experiment I disconnected the electrical connector and drove it back and forth to work. No CEL, no codes pending or otherwise. Anyone have any idea what it is for or what it does?

 

It's a heater, for air going into the crankcase. Probably only active during cold weather. Mines been removed for a couple years with no bad effects.

 

Did you ever get a CEL or throw a code? It seems weird to be an inlet into the crankcase when right in front of the turbo inlet. That means the negative pressure of the crankcase would be higher (more negative?) than the turbo and the check valve in the valve cover didn't work. I seem to remember seeing a PCV schematic somewhere on the forum. Maybe I will learn something today.

 

Nope, no codes or CEL, but the plumbing is still in place. Only the heater unit is removed and electrical connection taped up. Using a dual OCC, but this side is almost always dry.