My 2003 Dodge Durango has the check engine light on, and since it's due for a smog check to renew my tags, I went to AutoZone to get a code reader. The device cost $129.99 and returned two codes: P044
Inspect the gap between the rubber seal and the metal filler neck. If the metal part has oxidized, it may cause the rubber to separate, leading to a leak. In such cases, replacing the filler neck might resolve the issue. During a smoke test, use a laser pointer aimed at the fuel cap (with cap securely installed) to detect very small leaks that are not visible to the naked eye.
A smoke test and basic diagnostic check would typically cost less than your code reader. On Dodge vehicles, especially models like the 2003 Durango, P0440 is often caused by issues with the Leak Detection Pump (LDP) or Evaporative Emission System Integrity Module (ESIM). There are many forum posts discussing these specific codes on Dodge vehicles—searching for 'Dodge P0440 LDP' can provide more detailed troubleshooting steps.