[A8] Evap system non-leak

[Rich, Jack]

My A8's check engine light is perennially on, with the code for an evaporative system leak.  My mechanic has checked it twice, and cannot detect a leak.  That leads me to think perhaps the sensor is bad.  Any other ideas?  Anyone know where the sensor is that might tell the ECU there is an evaporative system leak, or how it should know this fact?

TIA,

Jack Rich
Senior Member of Technical Staff
Kronos
www.kronos.com
Improving the Performance of People and Business(tm)