P0456low severityPowertrain

EVAP System Leak Detected (Very Small Leak)

on 2002 Infiniti QX4 3.5L V6 · RWD

What this code means

A very small leak has been detected in the EVAP system. These are the hardest EVAP leaks to find.

Symptoms

  • Check Engine Light
  • Very slight fuel smell possible

Common causes

  • Gas cap seal worn
  • Micro-crack in EVAP hose
  • O-ring deterioration
  • Charcoal canister hairline crack
  • Fuel tank seal degradation

Diagnostic steps

  1. Check and replace gas cap first
  2. Smoke test EVAP system at low pressure
  3. Inspect all hose connections
  4. Check canister and all seals
  5. May need to pressurize fuel tank

Repair notes

Replace gas cap first. If code returns, smoke test is essential. Very small leaks can be time-consuming to locate.

Other Powertrain codes on this vehicle

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