Boost Solenoid - Focus Mk2 ST RS

Made by Pierburg the manufacturer of the genuine Ford part to exactly the same spec.

The boost control solenoid on the Ford Focus ST225 is located behind the turbo and is responsible for controlling the turbo actuator through the various stages of commanded boost.

The solenoid itself is manufactured by Pierburg and is found to be a very reliable and maintenance free component, however if you are experiencing problems with your commanded boost or any lumpiness when coming on or off the throttle this may be the culprit and certainly worth changing, especially on vehicles running heavy mods.