P0440 on Jeep Wrangler
EVAP System
Methodology: Reviewed against the SAE J2012 generic DTC definition and NHTSA owner-complaint patterns, then scoped to Jeep Wrangler context without treating complaints as confirmed diagnoses.
Sources: SAE/OBD-II definitions, manufacturer service information, and public reliability reports (including NHTSA where applicable).
- SAE J2012 Diagnostic Trouble Code Definitions — Generic diagnostic trouble code definition reference for P0440.
- NHTSA recalls, complaints, and manufacturer communications — Used to check public owner complaint context, recall status, and safety-related manufacturer communications by VIN or vehicle.
Limits: Guidance is informational and may not match every model-year or revision. Confirm with the official manual and diagnostics before replacing parts. For safety-critical or electrical work, use a qualified technician.
What P0440 Means on Your Jeep Wrangler
P0440 is a diagnostic trouble code indicating: EVAP System. This code relates to the emission controls system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.
Real Jeep Wrangler Owner Reports
Source: NHTSA Complaints Database
"A large amount of fuel violently erupts from tank mouth when filling and overflows onto the vehicle, ground & myself. this occurs at each complete fill-up. this 2005 jeep wrangler sporadically trips obd-2 check engine codes for emission evaporative components, in the p0440-p0456 range."
"When fueling vehicle, fuel spits back and overflows every time nearing full tank. also sets check engine light p0440. potential fire hazard."
All reports filed by vehicle owners directly with the U.S. Department of Transportation.
📊 Complaint Trend by Model Year
Common Causes on Jeep Wrangler
Based on NHTSA complaint component analysis for this vehicle.
What To Do Next
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1
Check for recalls on YOUR VIN
Go to nhtsa.gov/recalls and enter your VIN. If your vehicle is covered, repairs are free.
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2
Get a proper diagnosis
A code alone doesn't tell you the exact failed part. A diagnostic at a shop ($50–$150) pinpoints the root cause before you spend money on parts.
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3
Compare repair quotes
Get 2–3 quotes. Dealer vs. independent shop prices often differ 30–50% for the same repair.