Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Test NTC-7B - Checking Oxygen (O2) Sensor Switching
1984 Plymouth Horizon Base, 1.6 ASECTION Test NTC-7B - Checking Oxygen (O2) Sensor Switching
WARNING: This page is about a different car, the 1994 Plymouth Acclaim and 1994 Dodge Spirit. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
For circuit and connector terminal identification, see CONNECTOR IDENTIFICATION DIRECTORY TABLE
. For wiring diagrams, see WIRING DIAGRAMS
.
- Allow engine to idle. Inspect engine for vacuum leaks. Repair vacuum leaks as necessary. Perform TEST VER-2. If no vacuum leaks exist, using DRB, read O2 sensor signal voltage.
- If voltage is more than 0.1 volt, go to step 4). If voltage is less than 0.1 volt, turn ignition off. Disconnect O2 sensor connector. Disconnect Powertrain Control Module (PCM) connector. Put DRB in ohmmeter mode. Using DRB, check resistance of O2 sensor connector Black/Dark Green wire.
- If resistance is less than 10 ohms, repair short to ground in Black/Dark Green wire. Perform TEST VER-2 . If resistance is more than 10 ohms, replace O2 sensor. Perform TEST VER-2.
- Turn engine off. Replace O2 sensor. Turn ignition on. Using DRB, reset adaptive fuel memory. Start engine. Allow engine to reach normal operating temperature.
- Using DRB, read O2 sensor state. If O2 sensor state is switching, repair is complete. Perform TEST VER-2. If O2 sensor state is not switching, go to TEST NTC-15A .
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.