* Gas Cap: The most common culprit is a loose or faulty gas cap. The EVAP system prevents fuel vapors from escaping into the atmosphere. A poorly sealed gas cap allows these vapors to escape, triggering the light. This is the easiest and cheapest fix – try tightening the gas cap securely.
* EVAP System Leak: If tightening the gas cap doesn't work, there might be a leak somewhere else in the EVAP system. This could be a cracked hose, a faulty purge valve, or a problem with the canister itself. These components need professional diagnosis and repair.
* Overfilling: While less likely to cause an immediate light, overfilling the tank can sometimes force fuel into the EVAP system, leading to a malfunction.
* Other Less Likely Issues (but possible): While less probable, a sensor related to fuel level or pressure could be malfunctioning and falsely triggering the light after a significant fuel level change.
What to do:
1. Tighten the gas cap: This is the first step. Drive for a short distance (a few miles) and see if the light goes off. If it does, you likely solved the problem.
2. Get the codes read: If the light stays on, take your Explorer to an auto parts store (like AutoZone or Advance Auto Parts). They can usually read the diagnostic trouble codes (DTCs) for free. This will pinpoint the exact problem area.
3. Professional repair: Based on the DTCs, you'll need to either fix the problem yourself (if you're mechanically inclined) or have a mechanic diagnose and repair the EVAP system leak.
Ignoring the check engine light can lead to further damage and more expensive repairs. It's best to address the issue promptly.
