Located as part of the Oil Separator assembly - The red / orange grommet is furnished with the unit.
This is a small but, critical component, as it is important to not have the
crankcase vapors freeze (water vapor is present).
Oil and water
emulsification forms when vapors come in contact with cooler temperatures, freeze and ice crystals can then easily erode the turbocharger intake blades. Sounds very strange but it is true.
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Detailed Description
Sprinter 2004-2006
Sprinter II 2007-2018 3.0L V6
Sprinter II 2014-2016 2.1L 4 CYL
Sprinter III 2019+ 3.0L V6
If you only need the grommet for this sensor, it is shown below.