P0454

EVAP System Pressure Sensor/Switch Circuit Intermittent/Erratic

Car Fault Codes Emissions & exhaust

Can you still drive? Yes, normally

Who can fix it? Needs a workshop

Typical repair time 30 minutes – 3 hours

Typical cost SAR 100 to 900

What it means

The engine computer has detected that the fuel tank pressure sensor signal drops out or jumps suddenly in a way that does not match normal pressure changes. This usually points to a poor connection in the connector or wiring more than to a failed sensor.

Symptoms4

Check engine light on, possibly going off and coming back.
Usually no driving symptoms.
EVAP self-test stops running.
Failed emissions test.

Possible causes5

Loose connector or corroded terminals.
Corroded or partly broken wire under the vehicle affected by vibration.
Intermittent internal fault in the tank pressure sensor.
Water inside the connector.
Weak shared ground.

How to diagnose5

Watch the sensor reading as a graph on a scan tool to spot jumps.
Gently move the connector and wiring while watching to find the poor connection.
Inspect the connector terminals for corrosion or looseness.
Measure the reference voltage and ground while wiggling the wiring.
Inspect the wiring route under the vehicle for chafing.

How to fix5

Clean and tighten the connector terminals or replace the connector.
Repair and secure the corroded wire.
Repair the weak ground point.
Replace the tank pressure sensor if the jumps continue with good wiring.
Clear the codes and watch the reading to confirm it is stable.

Repair cost

0–500

500–2,000

2,000–5,000

5,000+

In Saudi riyals; the highlighted part is the expected range for this fault.

The fix is often a low-cost connector cleaning or wire repair; the cost rises if a new sensor is needed and the tank must be lowered.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions

Why does the check engine light go off and come back?

Because the fault is intermittent; it appears with vibration or moisture and disappears otherwise, which suggests a poor wiring connection.

Should I replace the sensor right away?

No. Check the connector and wiring first, since most intermittent faults come from a poor connection rather than the sensor.

This guide is for information only and does not replace an inspection by a qualified technician. If the fault involves brakes, steering, engine temperature, electrics or refrigerant, do not attempt the repair yourself.

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