P0457low severityPowertrain
Evaporative Emission System Leak Detected (Fuel Cap Loose/Off)
on 2000 Audi A6 2.7L Turbo V6 · AWD
What this code means
The EVAP system detected a large leak, typically from a loose, missing, or improperly sealed fuel cap. It can also indicate a disconnected EVAP hose.
Symptoms
- Check engine light on
- Fuel odor near vehicle
- Failed emissions test
Common causes
- Loose or missing fuel cap
- Worn fuel cap seal
- Disconnected EVAP hose
- Damaged filler neck
Diagnostic steps
- Check and retighten fuel cap
- Inspect cap seal for cracks
- Inspect EVAP hoses for disconnection
- Perform EVAP smoke test to confirm seal
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