Jeep Wrangler P0455: EVAP System → Leak Detected (Large)
The most frequent trouble code with the Jeep Wrangler The Code P0455. The trouble code refers to a number you receive when your Wrangler is plugged into an OBD2 scanner. It has to do the emission system. If there are any problems, P0455 indicates they have been fixed. Leakage large In the evaporative emissions control system (EVAP). It is frequently found alongside, or closely related to, other codes like P0420/P0430, and even P0441.
P0455: EVAP System → Leak Detected (Large)
The P0455 issue is not usually a threat to your Wrangler's driveability. Certainly anytime the service engine soon light is on, it’s good to deal with it as soon as possible though.
Jeep Wrangler P0455 Definition
The universal OBDII code P0455 can be used to diagnose trouble codes. It means that no matter what make or model vehicle you have, this code will be the same regardless. Technically, the code stands for:
System Gross Leak Evaporative Emission System
The EVAP captures any fuel vapor in the fuel tank, and transmits them to engines intake for ignition. When there is a large leak in the Jeep Wrangler’s EVAP system, it will throw the P0455 OBDII Code.
Jeep Wrangler P0455 OBDII Code Symptoms
A P0455 Code will usually not cause any symptoms except the ones listed below. Smells like gas The service engine soon light. It is possible to notice a slight dip in fuel economy.
The fuel tank and fuel filler tubes should smell particularly strong.
Fuel vapors are dealt with directly by the EVAP system. If these vapors are leaking from the system, you’ll often smell them faintly while operating the vehicle.
Problem Codes for Wrangler P0455
Many things can lead to the P0455 trouble code being triggered in Jeep Wranglers. The most frequent problems that trigger this code are:
- Hose for Evap System– The hose that carries the fuel vapor from the fuel tank to the intake manifold can begin to leak. The P0455 error code will be generated. 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. 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. The gasket may dry out especially if the vehicle is in dry conditions. When it dries out, the fuel tank can’t hold pressure anymore.
P0455 Diagnoses- Jeep Wrangler
The mechanic will have a lot of different tools at his disposal in order to determine the cause of your Jeep Wrangler P0455. The most commonly used methods to diagnose this code are:
- A 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 Check out the EVAP System. It includes the purge valve and line as well as the canister.
- To ensure that the cap can withstand pressure, the mechanic will check it. 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.
- Monitoring and checking the fuel tank pressure is a must.
- The mechanic will then perform the following tests after completing the above-mentioned checks:
- 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 Jeep Wrangler, the actual leak will most likely still look rather small. The “large” really is referring to how much pressure is being lost.
The Most Popular P0455 Fixes
These are some of the more common Wrangler solutions for P0455:
- Replacement of gas cap
- Replacement for EVAP Line
- 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.
It's a good idea to try and figure out why your Jeep Wrangler 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 Wrangler’s engine to stop running, it should not be treated lightly. There could be fuel contamination. You should pay extra attention to the level of your fuel tank and ensure that you're not leaking fuel. You should immediately take it in for repair or replacement.
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