Volkswagen Passat Forum banner

effinency

  1. Need help - getting CELs for Cat effinency low

    Volkswagen Passat B5 Discussion
    I have a an AUG 1.8T with a high flow CAT and APR stage 3 turbo and programing. Lately I have been getting CELs every couple of days. The ECU shows codes 16804 which is Cat efficiency low. The MAF is relatively new. Any suggestions on how to proceed? Should I replace my O2 sensor? If so, which...
Top