Dodge Ram P0455 Diagnostic Code

This is one of the most commonly encountered trouble codes for the Dodge Ram Is the Code P0455. The trouble code refers to a number you receive when your Ram is plugged into an OBDII scanner. If there's a problem, P0455 means that it is. Leakage large It is part of the evaporative emission controller system. This code is often found with or related to P0420,P0441 and, very frequently, P0440.

Your Ram'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. It's often associated with P0442. More information is available at Dodge Ram OBDII Code P0442.

Dodge Ram P0455 Description

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

System Gross Leak – Evaporative Emission System

The EVAP captures any fuel vapor in the fuel tank. They are then sent to the engines intake for ignition. When there is a large leak in the Dodge Ram’s EVAP system, it will throw the P0455 OBDII Code.

Dodge Ram P0455 OBDII Symptoms

A P0455 Code will usually not cause any symptoms except the ones listed below. Smells like gas And the service engine soon light. It is possible to notice a slight dip in fuel economy.

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.

Problem Code Ram P0455

The P0455 code can be triggered by many factors in Dodge Ram's Dodge Ram. The most likely causes of this code are:

• Evap System Hose– 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. It should be checked for tears or holes. 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. This could cause a drop in tank pressure which can throw off 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. It may be worth your time to get that message and a P0455 to ensure you don't waste any 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.

Dodge Ram P0455 Diagnostics

The mechanic will have a lot of different tools at his disposal in order to determine the cause of your Dodge Ram P0455. The most commonly used methods to diagnose this code are:

• The mechanic will usually check for any additional trouble codes. It is easier to diagnose problems if there are more codes. 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.
• Once the mechanic has determined the trouble codes associated with P0455, he or she will usually Take a look at 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 Dodge Ram, the actual leak will most likely still look rather small. The “large” really is referring to how much pressure is being lost.

The most common P0455 fixes

Below are some common Ram P0455 fix:

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

It is best to begin with the gas cap, and then work your way up to the fuel tanks. The gas cap is the most difficult and cost-effective item to replace.

Here’s a great video on How to test your gas tank.

It's a good idea to try and figure out why your Dodge Ram is throwing the P0455 code. This should help. You can add any additional information by leaving a comment.

Do you consider P0455 to be a serious concern?

While P0455 is not going to cause the Ram’s engine to stop running, it should not be treated lightly. There could be fuel contamination. Check your tank regularly to make sure there is no fuel leaking. It is best to have it checked and dealt with immediately.