Chevy S10 P0455: EVAP System → Leak Detected (Large)

This is one of the most commonly encountered trouble codes for the Chevy S10 The P0455 Code. The trouble code refers to a number you receive when your S10 is plugged into an OBD2 scanner. It has to do the emission system. The P0455 code indicates that an emission problem exists. Large leak It is part of the evaporative emission management system (EVAP). This code is often found with or related to other codes such as P0420 and P0430.

P0455: EVAP System → Leak Detected (Large)

Your S10's drive-ability is generally not affected by P0455. Certainly anytime the service engine soon light is on, it’s good to deal with it as soon as possible though.

Chevy S10 P0455 Definition

P0455 refers to a general OBDII code. The code can be used regardless of the make and model of the vehicle. Technically speaking, this code refers to:

System Gross Leak Evaporative Emission System

The EVAP system collects fuel vapor from your fuel tank. It then sends it to the intake to ignite the engine in normal combustion. When there is a large leak in the Chevy S10’s EVAP system, it will throw the P0455 OBDII Code.

Chevy S10 P0455 OBDII Code Symptoms

The P0455 code is usually not accompanied with any other symptoms than those listed. Smells like gas And the service engine soon light. The slightest drop in fuel economy may also be noticeable.

Particular attention should be paid to the smell of fuel near the fuel tank or fuel filler tube.

The EVAP system is responsible for fuel vapors. If these vapors are leaking from the system, you’ll often smell them faintly while operating the vehicle.

Trouble codes for S10P0455

You can have the P0455 troublecode trigger on your Chevy S10 for many reasons. These are some of the more common issues that can trigger the P0455 trouble code in your Chevy S10.

• Hose of the Evap System– The hose that carries the fuel vapor from the fuel tank to the intake manifold can begin to leak. This can lead to the P0455 code. You should look for a hole or a tear in the code. This is the main problem that can cause the code.
• Vapor Canister Purge Valve– One of the most common causes of the P0455 code is the vapor canister purge valve. It’s really easy to replace. You will need to locate and take out a few clips.
• A Faulty Canister of Charcoal– The charcoal canister is often the cause of P0455.
• Fuel Tank Sending Unit– It is possible for the gasket that attaches the fuel sending unit to the gas tank to go bad. It can lower the tank pressure, which could throw out the code.
• Fuel Cap– A bad fuel cap can cause the code to be thrown for sure. Often, you’ll get a message informing you that the fuel cap is off even when it is on. You may not get the message but a P0455. This will save you time and money.
• Fuel Filler Neck– There is often a gasket where the fuel filler neck connects with the gas tank. It is possible for this gasket to dry, particularly if vehicles spend a lot of time in dry environments. When it dries out, the fuel tank can’t hold pressure anymore.

P0455 Diagnose- Chevy S10

To diagnose the problem with your Chevy S10's P0455, a mechanic can use a variety of tools. These are some of the common diagnostics that can be done for the code

• The mechanic will check for other codes. A mechanic will usually check for additional trouble codes to help diagnose the problem. That’s because when they appear together in certain combinations, there will often only be only a few conditions that will throw any combination of codes at one time.
• The mechanic will normally determine what trouble codes are associated with P0455. Check out the EVAP System. It includes the purge valve and line as well as the canister.
• A mechanic will examine the gas cap and verify that it is able to withstand high pressure. If you are getting a warning that your gas cap is off, even when it’s on, replacing it will more than likely clear this code.
• Monitor and check the pressure in your fuel tank.
• Following the inspections and repairs, the mechanic will conduct two more tests.
• A smoke test, and they’ll use a scan tool to confirm that the EVAP solenoids and valves are operating properly.

Here’s a pretty good video on diagnosing these leaks from Scotty Kilmer, if you are interested:

While the trouble code may state that there is a “large leak” in the EVAP system of your Chevy S10, the actual leak will most likely still look rather small. The “large” really is referring to how much pressure is being lost.

Commonly Used P0455 Fixes

Below are the top S10 P0455 solutions:

• Replacement of gas cap
• Replacing EVAP lines
• Replace charcoal canister
• Replacing the fuel tank

You should start with the gas caps and move on to the fuel tanks. This is because the gas caps are the easiest to replace and the least costly.

Here’s a great video on How to check your gas cap.

You will need to solve the problem. We trust this helped. Please feel free to add anything below.

Do you consider P0455 to be a serious concern?

While P0455 is not going to cause the S10’s engine to stop running, it should not be treated lightly. Fuel leaks could be a problem. Check your fuel level to make sure it is not leaked. It is best to have it checked and/or dealt with immediately.