What does this thing do in my fender.

**J-jizzle** · 10-10-2010 07:34 PM

I took my rear fender carpet out the other day for cleaning. This was behind it on the drivers side. What does it do?

**vortexjunkie** · 10-10-2010 07:36 PM

im going to go with it has something to do with relieving pressure build up in the gas tank... just my guess

**BASARAB** · 10-10-2010 07:36 PM

Leak detection pump

**AudiA4Turbo22** · 10-10-2010 07:45 PM

charcoal canister for fuel system.

**AUDIous** · 10-10-2010 07:47 PM

leak dection pump, it pressurizes the gas tank and evap system to test for leaks

**J-jizzle** · 10-10-2010 07:51 PM

Thanks for the info. When should this filter be replaced. It looks in ok shape.

**AudiA4Turbo22** · 10-10-2010 07:53 PM

i believe that is the filter that basically vents the air from the fuel tank to atmosphere after filtering the air. think hepa filter.

Thread: What does this thing do in my fender.