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.
2000 Pontiac Firefly (CANADA) L4-1.3LFACTORY OEM SERVICE PROCEDURE
Sensor 2
REMOVAL PROCEDURE
NOTE: Refer to Heated Oxygen and Oxygen Sensor Notice in Service Precautions.
IMPORTANT: The HO2S may be difficult to remove at temperatures of more than 48°C (120°F). Allow the engine to cool before attempting to remove the HO2S. Be careful when removing the sensor in order to prevent damage to the threads in the exhaust manifold.
CAUTION: Refer to Battery Disconnect Caution in Service Precautions.
1. Disconnect the negative battery cable.
2. Disconnect the electrical connector from the heated oxygen sensor (HO2S) 2.
3. Remove the HO2S 2 from the exhaust pipe.
INSTALLATION PROCEDURE
IMPORTANT: A new HO2S 2 comes with an anti-seize coating on the sensor threads. Avoid removing any of the anti-seize coating prior to installation. If the sensor is being reinstalled, apply an anti-seize compound to the threads before installation.
NOTE: Refer to Component Tightening Notice in Service Precautions.
1. Install the HO2S 2 to the exhaust pipe.
2. Tighten the HO2S 2.
Tighten
Tighten the sensor to 40-50 N.m (29-36 lb ft).
3. Connect the HO2S 2 electrical connector.
4. Connect the negative battery cable.
Factory Service Tools
Use the Manual With the Right Hardware
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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.