O2 Sensor - Upstream

Replace the upstream oxygen sensor(s) on a 1992 Dodge Viper 8.0L V10, including proper connector disconnect, sensor removal, and installation with anti-seize compound.

Warnings

Tools required

Parts

• Upstream oxygen sensor × 2 — Use OEM specification or equivalent (heated 4-wire sensor)
• Anti-seize compound (nickel-based) × 1 — Never-Seez or equivalent

Preparation

1. Park vehicle on level ground and apply parking brake.
2. Place wheel chocks behind rear wheels.
3. Allow exhaust system to cool completely (minimum 1 hour after engine shutdown).
4. Raise front of vehicle with floor jack and support securely on jack stands at manufacturer-specified jacking points.
5. Verify exhaust components are cool enough to touch safely.

Procedure

1. 1

   Locate upstream oxygen sensors
   Position yourself under the vehicle with adequate lighting. The upstream oxygen sensors are located in the exhaust system between the exhaust manifolds and catalytic converters. The V10 configuration has one sensor on each bank (driver side and passenger side). Each sensor is threaded into the exhaust pipe approximately 12-18 inches downstream from the exhaust manifold flanges.
2. 2

   Inspect sensor and bung condition
   Examine both oxygen sensor bungs (threaded bosses in exhaust pipes) for visible corrosion, damage, or exhaust leaks. Check sensor wiring for heat damage, chafing, or brittleness. If sensors are severely corroded or have been in place for many years, spray penetrating oil around the sensor threads and allow to soak for 15-20 minutes before removal.
3. 3

   Disconnect driver side oxygen sensor connector
   Trace the oxygen sensor wire from the driver side sensor up to its electrical connector. The connector is typically secured to the frame rail or body with a clip or tie. Release any retaining clips or ties securing the connector. Disconnect the electrical connector by pressing the release tab and pulling the connector halves apart. Ensure the connector remains clean and free from debris.
4. 4

   Remove driver side oxygen sensor
   Using the oxygen sensor socket and ratchet with extension, position the socket over the driver side oxygen sensor. The slotted socket allows the sensor wire to pass through. Turn counterclockwise to loosen and remove the sensor. If resistance is encountered, do not force — apply additional penetrating oil and allow more soak time. Remove the sensor completely and inspect the threads in the exhaust bung.
5. 5

   Disconnect passenger side oxygen sensor connector
   Locate the passenger side oxygen sensor electrical connector following the wire harness from the sensor. Release any retaining clips or ties. Press the connector release tab and separate the connector halves. Keep the connector protected from contamination.
6. 6

   Remove passenger side oxygen sensor
   Using the oxygen sensor socket and ratchet, position the tool over the passenger side oxygen sensor. Turn counterclockwise to loosen and remove. Handle the sensor carefully to avoid damaging the sensing element. Once removed, inspect the exhaust bung threads for damage or excessive carbon buildup.
7. 7

   Clean oxygen sensor bungs
   Use a wire brush to clean the threads in both oxygen sensor bungs. Remove any carbon deposits, old anti-seize compound, or debris from the threads. Ensure threads are clean and undamaged. If threads are stripped or damaged, the exhaust component must be repaired or replaced before proceeding.
8. 8

   Prepare new oxygen sensors
   Remove new oxygen sensors from packaging. Verify each sensor matches the original specification (heated 4-wire type). Apply a thin, even coat of nickel-based anti-seize compound to the sensor threads only — approximately 2-3 threads from the end. Do not allow anti-seize to contact the sensor tip, body, or electrical connections. Keep sensor wires away from anti-seize compound.
9. 9

   Install driver side oxygen sensor
   Carefully thread the driver side oxygen sensor into the exhaust bung by hand, routing the wire away from hot exhaust components. Hand-tighten the sensor fully to ensure proper thread engagement and prevent cross-threading. Using the oxygen sensor socket and torque wrench, tighten the sensor to specification. Route the sensor wire to avoid contact with exhaust components, suspension parts, or sharp edges.
   Torque spec

   O2 Sensor45 Nm (33 lb-ft)
10. 10

    Install passenger side oxygen sensor
    Thread the passenger side oxygen sensor into the exhaust bung by hand, routing the wire appropriately. Hand-tighten completely, then use the oxygen sensor socket and torque wrench to tighten to specification. Verify the wire routing avoids heat sources and potential chafing points.
    Torque spec

    O2 Sensor45 Nm (33 lb-ft)
11. 11

    Reconnect electrical connectors
    Connect the driver side oxygen sensor electrical connector, ensuring the connector halves engage fully with an audible click. Secure the connector to the frame or body using the original clips or ties. Repeat for the passenger side sensor connector. Verify both connections are secure and wires are properly routed away from exhaust heat and moving components.
12. 12

    Lower vehicle and clear codes
    Remove jack stands and carefully lower the vehicle to the ground. If the vehicle's check engine light was illuminated due to oxygen sensor issues, clear diagnostic trouble codes using a Chrysler DRB scan tool (OBD-I) or by disconnecting the negative battery terminal for 30 seconds (this will also clear radio presets and other memory settings).

Reassembly

1. No disassembly was required for this procedure.
2. Ensure all electrical connectors are fully seated and secured with retaining clips.
3. Verify oxygen sensor wires are routed away from exhaust heat and do not contact moving suspension components.

Verification

• Start the engine and allow it to reach operating temperature while monitoring for exhaust leaks around the oxygen sensor bungs.
• Inspect both sensor installation points for any signs of exhaust gas escaping (visible smoke, hissing sound, or soot buildup).
• If equipped with OBD-II scan tool, monitor oxygen sensor live data to verify both sensors are reading voltage fluctuations (typically 0.1-0.9V in closed loop operation).
• Test drive the vehicle for 10-15 minutes, including varied throttle conditions, to allow the engine control module to enter closed-loop operation and verify sensor function.
• Check for diagnostic trouble codes after test drive — no oxygen sensor codes should be present if installation was successful.
• Perform a final visual inspection of sensor wire routing to ensure no contact with hot or moving components.

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