Vacuum Hose Atached To Air Filter Box

[Buncers]

Does anyone know the function of the vacuum hose attached to the side of the air filter on a 1.9 TDI Galaxy.

 

Does it affect how the engine runs and if so how ?

 

Would it affect my emissions ?

[seatkid]

It seems to be attached to a solenoid valve which I think is the TCS (turbo control solenoid)

 

I doubt it will effect emissions, rather performance.

[plwsm]

I think it's the atmospheric pressure inlet for the vacuum system. Basically, the way the turbo (and EGR) vacuum regulation works is that the ECU varies the duty cycle to the control solenoid valves. These switch between vacuum and atmospheric pressure to control the vacuum to the turbo and EGR valve.

I don't suppose it will effect the running if it gets disconnected, but it will probably suck in dirty air into the vacuum system which could eventually cause the values to stick. Taking in 'clean' air after the filter should prevent this.