P0454: Evaporative Emission System Pressure Sensor/Switch Intermittent

What does P0454 mean?

Fuel-tank pressure feedback is interrupted or erratic. A connector fault can appear only as the tank or body moves, while a sensor problem can become more obvious during the EVAP monitor.

Generic OBD-II definition: Evaporative Emission System Pressure Sensor/Switch Intermittent. Confirm applicability in your vehicle service information.

Common causes

• Intermittent pressure sensor
• Loose connector or damaged rear harness
• Vapor-system restriction or canister problem

Symptoms

• Steady check engine light
• Often no noticeable driving change
• EVAP readiness may not complete

Diagnostic focus

An abrupt voltage dropout should be separated from a real pressure change as purge or vent commands change. Plot the commands and pressure together if the scan tool supports them.

Can I keep driving with P0454?

Severity: Low With normal running and no fuel smell or leakage, arrange an emissions-system check. If you smell strong fuel vapor or see a leak, stop safely and have it inspected; keep ignition sources away.

If the check engine light is flashing or the car runs badly, stop driving and have it checked.

Typical fixes

• Save freeze-frame and EVAP data
• Graph tank-pressure feedback while inspecting accessible wiring
• Test the circuit before undertaking a leak or canister repair

Sources & review

• OBD-Codes.com: P0454
• TroubleCodes.net: generic code definitions

Definitions and diagnostic background checked 2026-11-06. Generic guidance, not a substitute for the service procedure for your exact year, engine, and transmission.