P0457: EVAP System Leak Detected (fuel cap loose/off)
What Does P0457 Mean?
P0457 is a diagnostic trouble code indicating: EVAP System Leak Detected (fuel cap loose/off). This code relates to the emission controls system. It has been reported in NHTSA complaints across 4 different vehicle models.
The emission control system reduces harmful exhaust pollutants through several subsystems: EGR (Exhaust Gas Recirculation) recirculates a portion of exhaust back into the intake to lower combustion temperatures and reduce NOx. The secondary air injection system pumps fresh air into the exhaust during cold starts to help the catalytic converter light off faster. The catalytic converter converts CO, HC, and NOx into CO2, H2O, and N2. The EVAP system captures fuel vapors from the tank and purges them into the engine for combustion. When any of these systems malfunction, the vehicle will fail emissions testing and the ECM will set a DTC.
Symptoms of P0457
- ⚠️ Check engine light on
- ⚠️ Failed emissions/smog test
- ⚠️ Possible rough idle or stalling (EGR stuck open)
- ⚠️ Fuel smell (EVAP leak)
- ⚠️ Reduced performance in some cases
- ⚠️ Increased tailpipe emissions
Common Causes
- 🔍 Carbon buildup causing EGR valve to stick
- 🔍 EVAP system leak (gas cap, hose, canister, purge valve)
- 🔍 Catalytic converter below efficiency threshold (aging)
- 🔍 Secondary air pump failure or check valve stuck
- 🔍 Wiring or vacuum line issue in emission control circuit
P0457 Reports by Year
Real Owner Reports
From NHTSA complaint database — actual owner descriptions.
""CHECK FUEL CAP" LIGHT ILLUMINATES IN '00-'05 FORD EXPLORERS. THERE HAVE BEEN HUNDREDS OF REPORTS OF THIS ISSUE OCCURRING, AND IT IS THE RESULT OF EMISSION FAILURE PARTS IN THESE VEHICLES. EACH INSPECTION AND REPLACEMENT OF THESE PARTS IS COSTING OWNERS THOUSANDS OF DOLLARS IN REPAIRS, AND IS CLEA"
— Ford Explorer owner, 04/06/2011
"FUEL CAP CODES, EMISSION CONTROL CODES AND THROTTLE ACTUATOR CONTROL CODE ARE NOW ON ALL THE TIME. I HAD TAKEN IT BACK TO FORD, BUT LIGHT HAD WENT OUT AT THE TIME. I WAS TOLD THAT THE CODES DO NOT LOG IN ECM. I WAS TOLD THEY COULD HOOK UP EQUIPMENT, THERE WOULD BE NO CODES AND THE COST $90.00. I LEF"
— Ford Fusion owner, 06/01/2013
"DURING INITIAL ACCELERATION THE CAR WILL LOSE POWER AND START SHAKING SPORADICALLY. THE CAR WILL NOT STALL BUT IT DOES NOT ACCELERATE EVEN WHEN THE GAS PEDDLE IS DEPRESSED. THE CAR HAS TO BE RESTARTED TO STOP BEHAVIOR. CHECK ENGINE LIGHT APPEARED AFTER THE BEHAVIOR PERSISTED FOR ABOUT A WEEK. BROUGH"
— Ford Fusion owner, 06/19/2013
Source: NHTSA Complaints Database
Most Reported Vehicles for P0457
Based on NHTSA owner complaint data.
| # | Vehicle | Reports |
|---|---|---|
| 1 | FORD FUSION | |
| 2 | FORD ESCAPE | |
| 3 | FORD EXPLORER | |
| 4 | CHRYSLER PACIFICA |
P0457 Reports by Vehicle
Detailed NHTSA complaint analysis for each vehicle model.
Diagnostic Tips
- For EVAP codes: start with the gas cap — tighten it and clear the code. If it returns, use a smoke machine to find the leak
- For EGR codes: remove and inspect the EGR valve — carbon buildup causing sticking is extremely common and cleanable
- For catalyst codes: check upstream O2 sensor first — a bad sensor can falsely report low catalyst efficiency
- For secondary air codes: listen for the air pump running during cold start — it should run for 30-90 seconds
Common Mistakes to Avoid
- ❌ Replacing the catalytic converter based on a P0420/P0430 code alone — diagnose the root cause first (O2 sensor, exhaust leak, engine running rich)
- ❌ Ignoring a loose gas cap as the cause of EVAP codes — this is literally the #1 cause and the cheapest fix
- ❌ Using aftermarket catalytic converters in states with strict emissions laws (California) — CARB-compliant converters are required
Frequently Asked Questions
Will I pass emissions with a check engine light on?
Can I just clear the code before emissions testing?
How much does a catalytic converter cost?
What To Do Next
Possible Fixes
- 🔧 Clean or replace EGR valve
- 🔧 Replace gas cap (EVAP codes)
- 🔧 Replace EVAP purge or vent solenoid
- 🔧 Replace catalytic converter
- 🔧 Replace secondary air pump or check valve
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1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
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Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
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Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.