Acura TSX P1457: EVAP Leakage (Canister System)

P1457 is a common trouble code in vehicles made by Honda. It is a Honda specific code, which means that it has the same meaning in any vehicle manufactured by Honda (including Acura).

P1457 indicates that there is a leakage coming from the EVAP canister system.  It is typically caused by an issue with the gas cap, or failure to snug it all the way.  There are other issues that can cause it as well. We’ll cover those directly below.  

Let’s hope it’s the gas cap.  They only take a minute to replace and are very cheap.

P1457 Acura TSX


P1457 Symptoms Acura TSX

Symptoms of P1457 typically include the smell of fuel, and the check engine light. It is telling you the TSX’s diagnostic computer believes that the EVAP leakage is coming from the fuel tank, which is why starting with the fuel cap is a good idea.


Acura TSX P1457 Causes

As stated above, P1457  is often caused by either a faulty, loose, or missing fuel cap.  Start by inspecting it.  Does the seal look even and smooth?  Are there any signs of dry rot?  Take a good look at it before troubleshooting the EVAP canister and system.

If that’s not it, it’ll usually be the EVAP system itself. Certainly every model year is going to have its own set of circumstances, but these are the most likely causes of P1457 in the Acura TSX in general.

Fuel Cap– The fuel cap is the best place to start diagnosing P1457. It’s the most likely reason that the code has been thrown, as well as the least expensive and easiest to access part to replace.

Here is a great video on how a gas cap can cause trouble codes. When they have gone bad, gas caps typically will fail to tighten. You may also be getting a message that says to tighten the gas cap. Here’s a good article on the symptoms of a bad gas cap.


Fuel filler neck/input/pressure sensor– Take a look at the fuel filler neck and see if there is any damage or debris that could be keeping the fuel cap from making a tight seal. There’s an O-Ring that will connect the fuel filler neck to the gas tank. If it has dried out or broken, the fuel tank will no longer be able to pressurize and P1457 will be thrown.  

The fuel tank pressure sensor can also cause this code to be thrown, although it’s not very likely.


EVAP System– The Evaporative Emissions Control System carries fuel vapor from the fuel tank to the intake manifold. If it develops a leak, it’ll often also throw codes such as P0455, P0456, or P0457,

These codes indicate that there is an EVAP leak. The only difference in them is they each indicate a different size leak. When the EVAP system is leaking, it can throw P1457 because it would depressurize the fuel tank much in the same way as a missing gas cap would.

Here’s a video on how to test the EVAP vent canister Valve with P1457 in a Honda made vehicle:




Most of the time, replacing the fuel cap will clear P1457. It may take the vehicle awhile to reset the code. Make sure to drive it a little before inspecting the fuel filler neck or checking the EVAP system. If there’s anything you’d like to add, please leave a comment below. Good luck!

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