Chevy Impala P0449 Code Diagnosis: EVAP System

This is a very common problem with the Chevy Impala The Code P0449. The trouble code refers to a number you receive when your Impala is connected to a computer. OBDII scanner. It deals with the evaporative emissions management system. It is frequently found alongside, or closely related to, other codes such as P0420 and P0446.

P0449: Evaporative Emission Control System Vent Valve/Solenoid Circuit Malfunction

Your Impala's driveability is not at risk from P0449. Certainly anytime the service engine soon light is on, it’s good to deal with it as soon as possible though. You can also use a scanner to check if your valve is working correctly. They are common in shops. There’s a link towards the bottom the page on exactly how to perform that procedure. This article will show you how to diagnose and fix the problem.

Chevy Impala P0449 Definition

The universal OBDII code P0449 can be used to diagnose trouble codes. It means that no matter what make or model vehicle it is, P0449 will be the same code (Impala or otherwise) as long as the vehicle was made after 1996.

If P0449 is displayed, it means that either the solenoid circuit or the valve controlling the evaporation system are not working correctly. Depending on your vehicle's model, the EVAP cycle fuel vapor out of the tank into an intake manifold. This system can fail to properly deal with fuel vapor if it malfunctions.

ECM (Engine Control module) has identified a problem in the circuit that controls the vent which releases fuel vapor. Soon, the service engine will follow this up.

Chevy Impala P0449 OBDII Code Symptoms

A P0449 Code will not usually be associated with other noticeable symptoms. The smell of gas The service engine soon light. The slightest drop in fuel economy may also be noticeable.

The fuel tank and fuel filler tubes should smell particularly strong.

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.

Impala Trouble Code P0449

P0449 can happen for many reasons in Chevy Impala. These are some of the more common issues that can trigger the P0449 code. Here's a video explaining the process.

• 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 P0449. This will save you time and money.
• EVAP 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 P0449 error 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 P0449 code is the vapor canister purge valve. It’s really easy to replace. You will need to locate and take out a few clips. Here’s How to test a purge valle (YouTube).
• Wiring and Fuse Problems– If the wiring going to the valve has been compromise, it’ll lead to the P0449.
• 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 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, it may erroneously throw P0449.

P0449 Chevy Impala Diagnosis

To diagnose the problem with your Chevy Impala's P0449, a mechanic will have a variety of tools at his/her disposal. These are some of the common diagnostics that can be done for the code

• 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.
• A mechanic will often check for additional 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 P0449, he or she will usually Take a look at the EVAP system. It includes the purge valve and line as well as the canister.
• Monitoring and checking the fuel tank pressure is a must.
• After for the checks and fixes listed above, the mechanic will perform two tests: A smoke test, and they’ll use a scan tool to confirm that the EVAP solenoids and valves are operating properly.

Are you still having problems? Here’s a Super technical video This is a great article on how to diagnose P0449.

Most common P0449 fixes

These are some of the most popular Impala P0449 solutions:

• Replacing the gas cap
• Replacement for EVAP Line
• Vent valve replacement
• Wiring repair

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.

We wish you all the best in finding out why your Chevy Impala is throwing the P0449 code. This should help. Please feel free to add anything below.

Are P0449 Serious Concerns?

While P0449 is not going to cause the Impala’s engine to stop running, it should not be treated lightly. Fuel leaks could be a problem. Check your tank regularly to make sure there is no fuel leaking. It is best to have it checked and/or dealt with immediately.