Guide To P0457 OBD Error Code Solutions

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Check Engine Light on and fuel vapour odor from the vehicle are the two major symptoms that can be an indication of leakages in the EVAP system and leading to OBD code P0457 getting stored in the Powertrain Control Module (PCM).

Code P0457 stands for Evaporative Emission System Leak Detected (Fuel Cap Loose/Off).

Although this code doesn't cause drivability problems, but states that a vacuum leak is present that compromises the evaporative emission system operation. Automobiles require two types of controls over emissions -- passive and active. The active portion relates to the fuel ratio control and the catalytic converter ability to convert carbon monoxide, oxides of nitrogen and hydrocarbons into harmless water and carbon dioxide. The passive relates to this P0457 code. Fuel vapour accounts for 20 percent of the harmful emissions through evaporation. To prevent these vapours from entering the atmosphere they are contained within the fuel system and re-enter the engine via the intake manifold.

The evaporative emission system consists of the fuel tank, a vacuum hose to the charcoal canister for containing the fuel vapours, pressure sensor on the fuel tank, purge valve on the charcoal canister, vacuum hose to the filler neck shut off valve and vacuum hose from the charcoal canister purge valve to the intake manifold. When the engine is off, the vent shut off valve and canister purge valve are closed. The fuel can't escape into the atmosphere. When the engine starts, the purge valve on the canister opens to allow the trapped fuel vapour to be drawn by engine vacuum into the intake manifold. At the same time the vent shut off valve also opens to allow a small amount of air to enter the canister and mix with the fuel vapour for a better mixture. Once vented and the pressure sensor in the tank shows a significant drop, both valves close sealing the system once again.

What causes this problem with the EVAP System Leak (Fuel Cap Loose/Off)?

• A missing, cracked, or loose gas cap
• A cracked or rotten hose
• A cracked vacuum canister

1. Fuel Tank Filler Neck - Check for faulty tank filler neck and replace it immediately, if required.
2. Fuel Tank Vent Valve - Fuel tank vent valve can be damaged and might need replacement. Buy new vent valve and replace it now!
3. Vapour Canister Valve - If the vapour canister valve is faulty, it can allow fuel vapours to escape, thus reducing the performance. Buy new canister valve now!
4. Fuel Tank - Check for leaky and damaged fuel tanks and replace it immediately, if needed.
5. Fuel Tank Cap - Check for loose cap or the one that may be damaged or missing and replace it now!
6. Diagnostic Tools - Experienced mechanic will require quality diagnostic tools to resolve OBD code errors. Buy new tools from us!

We at Parts Avatar Canada care for our customers, and that’s why we will help you to diagnose P0457 code by listing out some major symptoms. They are mentioned below as follows:

Common Symptoms

• Check Engine Light illuminated
• Noticeable fuel odor caused by the release of fuel vapours

Have a look at some ways with which you can correct the P0457 code:

• Fuel cap should be tight and should be replace in needed
• Fuel tank pressure sensor repair or replacement
• Damaged wiring to the fuel tank pressure sensor to be repaired

However, if you face any issue then we have stocked a wide range of best priced Fuel Tank Filler Neck, Evaporative Vent Valve, EVAP Purge Switch, Carbon Canister, Fuel Tank, Fuel Cap and more to help you out in fixing your car.

If you want to easily diagnose this fault code, then all you have to do is to follow the steps which are mentioned below:

• For any EVAP code, the mechanic shall first inspect the fuel cap, tighten it, clear the code, and reset the engine computer. 
• Then, test the vehicle to see if the code returns. If not, then it’s just another case of “loose gas cap syndrome.” However, if the code persists, the fuel tank pressure sensor could be the culprit. 
• Use a professional OBD-II scanner, and look at the fuel tank pressure readings to see if the engine computer is reading vacuum from the sensor. 
• If not, the wiring from the sensor should be inspected to ensure there isn’t a communication error before replacing the pressure sensor.
• Inspect for the faults in the PCM and replace or reprogram it as required. Sometimes, the fault in the PCM can result in wrong error code or multiple error codes getting stored in the system. Thus, proper check for all the components is required

Common Mistakes When Diagnosing the P0457 Code

Always check for loose caps and damaged valves first as well as faulty wirings before going to sensors and other costly components for replacement.

• Check for faulty wiring and connections
• Faulty sensors and fuel pumps
• EVAP canister valve errors
• Powertrain Control Module failure
• Fuel tank pressure sensor faulty
• Pressure sensor connector faults
• Fuel tank filler neck problematic