Lincoln MKX Code Diagnosis

The most frequent trouble code with the Lincoln MKX Is the Code P0455. The trouble code refers to a number you receive when your MKX is plugged into an OBDII scanner. If there's a P0455, it means that the problem is solved. Leakage large It is part of the evaporative emission controller system. It is frequently found in conjunction with other codes such as P0420 or P0441.

The P0455 issue is not usually a threat to your MKX's driveability. 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 Lincoln MKX OBDII Code P0442.

Lincoln MKX Definition

P0455 refers to a general OBDII trouble code. The code can be used regardless of the make and model of the vehicle. The code is technically:

System Gross Leak – Evaporative Emission System

The EVAP captures any fuel vapor in the fuel tank. They are then sent to the intake of the engine to start the combustion process. When there is a large leak in the Lincoln MKX’s EVAP system, it will throw the P0455 OBDII Code.

Lincoln MKX OBDII Code Signs

A P0455 Code will usually not cause any symptoms except the ones listed below. The smell of gas And the service engine soon light. The slightest drop in fuel economy may also be noticeable.

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

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.

MKX Trouble Code P0455

P0455 Trouble code can be triggered in Lincoln MKX by many factors. The most frequent problems that can trigger the 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. 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.
• The Faulty Charcoal Caister– 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. 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 Diagnostics- Lincoln MKX

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

• The mechanic will check to make sure there are no 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. Take a look at the EVAP system. These include the line and purge valve.
• 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.
• 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 Lincoln MKX, the actual leak will most likely still look rather small. The “large” really is referring to how much pressure is being lost.

Most common P0455 fixes

These are some of the more common MKX P0455 fix:

• Replacement of gas cap
• Replacement for EVAP lines
• Replace charcoal canister
• Change 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 check your gas cap.

It's your task to determine what caused the Lincoln MKX code P0455. This should help. Please feel free to add anything below.

Do you consider P0455 to be a serious concern?

While P0455 is not going to cause the MKX’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.