Corrado L4-1781cc 1.8L SOHC SC (PG) (1990)
Oxygen Sensor: Testing and Inspection
Control Checking
Oxygen sensor control, checking
CAUTION! Do Not use any sprays or compounds containing silicone on engines equipped with Oxygen sensors. Do Not use these compounds on or
near intake air system or near the Oxygen sensor. Silicone drawn into the intake air system is not burned during combustion and will lead to
contamination and malfunctioning of the Oxygen sensor.
Requirements
-
engine oil temperature 8O°C (176°F) minimum
-
idle speed OK
-
exhaust system between catalyst and cylinder head must be leak tight
-
coolant temperature sensor (blue) connected
-
voltage supply to OXS heater OK
- connect SUN 105 CO tester (or EPA approved equivalent) to CO tap tube using hose adaptor VW 1363/3
CAUTION! Hose must fit securely on CO tap tube to avoid measuring inaccuracies due to dilution or leakage.
- start engine and let idle for at least 2 minutes
- record CO content
- disconnect pressure regulator vacuum hose from intake manifold (arrow) and plug off
-
CO content must increase briefly then return to recorded value
If CO content does not drop back
- disconnect OXS heater harness connector (arrow)
- connect jumper wire from VW 1594 adaptor kit to OXS harness connector signal wire (arrow)
- alternately touch the free end of the adaptor wire to ground and battery positive
-
CO content must alternately increase and decrease
If YES
- replace Oxygen sensor
If NO
- check wiring between Oxygen sensor and Digifant control unit using wiring diagram, repair or replace as necessary
If wiring OK