Oxygen Sensor
- Oxygen sensor can not be tested directly but its control signal can be checked. Circuit tester having internal resistance of approximately 20,000 ohms is necessary to test circuit.
- Unplug oxygen sensor harness at connector. Insert fine wire into vehicle side connector. Set tester scale to 2V and connect positive lead of tester to fine wire.
- With negative lead of tester to ground and plugs reconnected, start engine. Check voltage when engine speed is momentarily increased. Tester needle should deflect within range of 0-0.8V.