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.
System Description
To monitor the EVAP control system, a fuel tank pressure sensor and an EVAP canister air (vent) valve are added to the system. See Fig 1. The monitoring system measures pressure change of closed EVAP system circuit under the depressurized condition. The system also measures pressure change of closed circuit to compensate evaporative pressure with the normal range pressure, if necessary. See Fig 2.
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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.