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) L3-1.0LFACTORY OEM SERVICE PROCEDURE
Loop Status
The scan tool displays Open Loop or Closed Loop. Closed Loop indicates that the PCM is controlling fuel delivery according to oxygen sensor voltage. Open Loop indicates that the PCM ignores the oxygen sensor voltage and bases the amount of fuel to be delivered on the TP sensor, the ECT sensor, and MAP sensor inputs.
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.