Checking EVAP canister

WARNING: This page does not describe the selected car, but rather 11 other vehicles, including the 1999 Volkswagen Jetta, 1999 Volkswagen GTI, 1998 Volkswagen Jetta, 1998 Volkswagen GTI, and 1997 Volkswagen Jetta. However, it is still accessible from the selected car via links, so may be relevant.

Remove air cleaner

Disconnect vent hose -1- from throttle valve housing -2-.
Connect vacuum pump US 8026/VAG 1390 to hose -1-.

Fig 1: Identifying Vacuum Hose Connections At Throttle Valve Housing
Disconnect vent hose -3- (from fuel tank) at EVAP canister -4- and connect to connection -A- of vacuum tester VAG 1368/US 9204.
Connect vacuum tester VAG 1368/US 9204 connection - B- to Evaporative Emission (EVAP) Canister.
Set vacuum tester to position -B-.
Operate vacuum pump US 8026/VAG 1390 several times.
- Vacuum must not build up.

If vacuum builds up:

Check breather connection -5- on Evaporative Emission (EVAP) Canister -4- for contamination. Clean as necessary.
Check EVAP canister purge regulator valve -N80- -6- for continuity and replace if necessary. See EVAP canister purge regulator valve -N80-, checking (Vehicles up to 1995) .