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
Long Term FT-1
The scan tool display is a positive or negative percentage. The PCM derives the Long Term Fuel Trim (FT) from the Short Term FT value. The Long Term FT represents a long term correction in the fuel delivery. A value of 0% indicates that fuel delivery requires no compensation in order to maintain the desired air/fuel ratio. A negative value, significantly below 0%, indicates that the fuel system is rich. When the fuel system is rich, the PCM reduces fuel delivery by decreasing injector pulse width. A positive value, significantly greater than 0%, indicates that a lean condition exists. During a lean condition the PCM increases fuel delivery by increasing injector pulse width. Fuel trim values at maximum authority may indicate an excessively rich or lean condition.
Factory Service Tools
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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.