5.3 Testing Oxygen Sensor System (Digifant II and Digifant I)

With the Digifant engine management system, the oxygen sensor provides just one of many inputs to the Digifant control unit, which it then processes in order to properly control the air/fuel mixture. Because there is no way to directly measure the injector opening time, which determines the air/fuel mixture, there is no direct way to observe or measure the operation of the oxygen sensor.

Oxygen sensor function can only be evaluated indirectly, using a carbon monoxide (CO) meter in the exhaust. If the necessary equipment and an experienced operator are not available, we recommend that the oxygen sensor be checked by an authorized Volkswagen dealer.