Engine Emission Control

Engine Emission Control

NOTE: Do not permanently remove or render inoperative any part of the vehicle emission control system including related hardware. Failure to comply may violate applicable state and federal law.

The engine emission control system consists of the PCV system.


PCV System

The PCV system:

- uses intake manifold vacuum to ventilate blow-by vapors from the crankcase.
- returns the vapors to the intake manifold for combustion.

The PCV system consists of the:

- crankcase ventilation tube.
- PCV valve.

The PCV valve:

- varies the amount of blow-by vapors returned to the intake manifold based on available engine vacuum.
- prevents combustion vapors backfiring into the crankcase.


Vehicle Emission Vacuum Routing

Taurus and Sable










Taurus X with Partial Zero Emissions Vehicle (PZEV)










Taurus X with Federal Emissions