P1457
FordUnable To Pull Vacuum In Tank
The EVAP system stores fuel vapors and checks whether it can create and detect vacuum in the tank. This code means the expected vacuum was not detected. A leak, a valve or hose problem, or an inaccurate pressure reading may be involved; the code alone does not identify a failed part. The check-engine light may be the only noticeable effect.
⚠️ Before You Begin (Safety First)
This is usually an emissions-system fault, not an immediate driving hazard. If you notice a strong or persistent fuel smell, see leaking fuel, or suspect a fuel leak, park safely, avoid flames and sparks, and have the vehicle inspected rather than continuing to drive.
Common Symptoms
- The check-engine light may be on, with no noticeable change in how the vehicle runs.
- A fuel-vapor odor may occur if the cause is a leak in the fuel-vapor system.
- The vehicle may fail an emissions inspection because the EVAP system is not completing its expected check.
Common Causes
- A loose, damaged, or poorly sealing fuel cap or cap seal may prevent the system from holding vacuum.
- A leak or disconnected, cracked, or damaged connection in the tank vapor lines or EVAP plumbing may prevent vacuum from building.
- An EVAP valve may not operate or seal as intended, preventing the system from creating or holding vacuum.
- A tank-pressure sensor or its electrical connection may provide an inaccurate reading, making it appear that vacuum was not achieved.
Diagnostic Steps
- Check whether the fuel cap is present, properly seated, and visibly damaged; a poor seal can let vapor escape.
- With the vehicle parked and cool, visually inspect accessible EVAP hoses and connections for obvious disconnection, damage, or fuel wetness; do not disconnect lines or work around ignition sources.
- Note any fuel odor and whether the check-engine light returns after the cap and accessible connections have been checked; this information can help guide diagnosis.
- Have a qualified technician test the EVAP system if the code returns or no obvious issue is found; visual checks cannot confirm that the system can create vacuum.
When to Call a Professional
Confirm the code and review available freeze-frame and EVAP data before replacing parts. Check the fuel cap and system connections, then use appropriate scan-data and EVAP leak-testing equipment to determine whether the system can create vacuum and whether the tank-pressure reading is credible. Exact tests depend on model, year and engine.
Compare component listings
Confirm diagnosis and vehicle fitment before buying. A listing does not prove that a part needs replacement. We may earn a commission from qualifying purchases.
Commonly Asked Questions
Does P1457 prove the fuel cap is bad?
No. The cap is one possible source of lost vacuum, but a leak elsewhere, a valve problem, or an inaccurate pressure reading can produce the same detected condition.
Can I drive with this code?
If the vehicle drives normally and there is no fuel odor or visible leak, the code is usually not an immediate drivability emergency. Stop and seek inspection if you detect a strong fuel smell or leaking fuel.
Why might there be no symptoms?
The EVAP system manages fuel vapors and its checks can fail without affecting normal engine operation. The warning light may be the only sign.
What test can distinguish a leak from a sensor or valve issue?
A technician can compare scan data with appropriate EVAP tests to check whether the system creates vacuum, holds it, and reports pressure plausibly. The exact procedure depends on the vehicle.
Browse Available Code Guides
Previous and next available guides in database record order, across makes. Adjacent entries may share a code number and do not necessarily describe related faults.