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.
EVAP System Leak Monitor
This monitor applies to DTCs P0442, P0450 and P0455. Following conditions must be met during the test:
- Engine coolant temperature must be 113°F (45°C) or less.
- Atmospheric temperature is 41-113°F (5-45°C).
- If automatic transmission, selector lever is in "D" range.
- If applicable, overdrive switch is in ON position.
- If applicable, pattern select switch is in OFF position.
Monitor takes about 8 minutes to complete. To run monitor, use illustration. See Fig 1 . Perform steps as follows:
- Remove all test equipment from vehicle and install all components and connectors that were removed or disconnected during testing.
- Start engine.
- Accelerate to 55-60 MPH.
- Travel for 200 seconds or more while keeping speed at 55-60 MPH (M/T: 5th gear).
- While keeping accelerator pedal opening degree constant, keep speed at 55-60 MPH for 150 seconds or more (this is when monitor runs).
- Return vehicle to shop and turn ignition off.
- Confirm DTC is not output. If DTC is output, go to appropriate DTC test in appropriate SELF-DIAGNOSTICS article.
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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.
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