LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Audi >> 1987 >> 5000 CS, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> BOSCH Cis-E System >> Testing >> Electrical Components >> Oxygen Sensor
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Oxygen Sensor

  1. Before testing oxygen sensor, ensure the following conditions are met: engine oil temperature is at 176°F (80°C) minimum, radiator fan must cycle at least once, pressure gauges NOT connected, exhaust system free of leaks, oxygen sensor control working correctly, oxygen sensor heating element functional, all electrical units turned off (radiator fan and A/C must be off during test), and engine speed at 3000 RPM for 2 minutes.
  2. Connect test harness between differential pressure regulator and vehicle harness. Connect multimeter to test harness. Run engine at idle. After 2 minutes running time, oxygen sensor will be operational.
  3. Check current reading at 3000 RPM. If reading fluctuates, oxygen sensor is good. If reading does not fluctuate at 3000 RPM, replace oxygen sensor.
scientia non olet · About LEMON Manuals