Possible fault causes
- Tank vent valve faulty (stuck open or closed)
- Tank vent valve not installed or installed incorrectly
- Line between active carbon filter and tank vent valve leaking/trapped/blocked
- Purge-air line between tank vent valve and intake manifold leaking/trapped/blocked
- Purge-air line between the tank vent valve and turbocharger (venturi pump) leaks
- Check valve between tank vent valve and intake manifold faulty or installed backward
- Check valve between tank vent valve and turbocharger (venturi pump) faulty or installed backward