Bob Petruska

The LPG pressurizes the the evap system at startup and then performs a leak down check for 5 minutes. If major or minor pressure drop develops it tiggers the corresponding code. This posted writeup indicates a vacuum is pulled on evap system to determine leaks which is totally opposite of how the B6 system works. Also, the B6, ECU does not control the rate of venting to the atmosphere. It's open or closed.

This write up for some other vehicle.