Vanagon F4-1970cc 2.0L (1982)
Oxygen Sensor: Testing and Inspection
Checking Oxygen Sensor, (Calif. only)
Note: Oxygen sensor is located in exhaust system (in front of catalytic converter). It produces varying voltages (up to 1 volt) dependent on oxygen
content of exhaust gases. These voltages are sent to electronic control unit which alter injection time accordingly. Oxygen sensor operates at all engine
speeds, except warm-up. During full throttle enrichment the oxygen sensor signal is not used.
Preconditions:
Engine oil temperature at least 60°C (140°F)
Air temperature 20°C (68°F). Before starting following test procedures, wait until intake air sensor housing has assumed room temperature
Work sequence
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Connect tachometer according to manufacturer's instructions
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Connect CO meter to test receptacle in front of converter (do not connect at tailpipe)
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Check idle speed and adjust if necessary
850 - 950 rpm
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Disconnect oxygen sensor wire 1 to control unit
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Check CO %
0.7 ±0.4%
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Let engine idle, disconnect vacuum hose 2 at pressure regulator 3 and plug hose
CO% must increase to approx. 2.5%
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Reconnect oxygen sensor wire 1
C0 must drop to 0.7 ±0.4% if oxygen sensor is OK
If NO, following components may be defective:
Oxygen sensor
Wire between oxygen sensor and control unit
Leak in exhaust system between catalytic converter and cylinder head
Checking The Wire Between Oxygen Sensor And Control Unit
