OBD Guide

P0456

EVAP System Leak Detected (very small leak)

P0456 is an OBD-II diagnostic trouble code meaning: EVAP System Leak Detected (very small leak). Common causes: loose or damaged gas cap, cracked or worn evap hoses. Estimated repair cost: $6–56.

Severity
Low
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$6–56 (est.)

Symptoms

  • Check Engine Light Is On
  • Slight increase in fuel consumption
  • The smell of gasoline in the cabin or near the car

Causes

  • Loose or damaged gas cap
  • Cracked or worn EVAP hoses
  • Purge valve (solenoid) malfunction
  • Leak in fuel tank or EVAP system connections
  • Broken or corroded system sensor wiring harness

How to Fix

  1. Check and tighten the gas cap if it is not securely closed.
  2. Visually inspect EVAP system hoses and connections for cracks or damage.
  3. Check the purge valve for blockage or malfunction
  4. Use a smoke generator to locate the leak (if visual inspection does not help)
  5. Check the pressure sensor in the fuel tank and its circuit for serviceability

Related codes

Error P0456 by Vehicle Brand

FAQ

What does the P0456 code mean?

P0456 is an OBD-II diagnostic trouble code that indicates: EVAP System Leak Detected (very small leak)

What causes a P0456 error code?

The most common causes of P0456 include: Loose or damaged gas cap; Cracked or worn EVAP hoses; Purge valve (solenoid) malfunction; Leak in fuel tank or EVAP system connections.

How do I fix a P0456 diagnostic trouble code?

To fix P0456: Check and tighten the gas cap if it is not securely closed.. Visually inspect EVAP system hoses and connections for cracks or damage.. Check the purge valve for blockage or malfunction. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P0456?

Do not drive — repair immediately

How much does it cost to fix P0456?

The estimated repair cost for P0456 is $6–56. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat