P0449 Chevy Tahoe | Drivetrain Resource

This is a very common problem with the Chevy Tahoe Is the Use code P0449. This is your trouble code. It is the reference number given when you plug in your Tahoe to an a OBDII scanner. The evaporative emission control system is P0449. 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

The P0449 problem is not usually a threat to your Tahoe's driveability. Certainly anytime the service engine soon light is on, it’s good to deal with it as soon as possible though. A scanner that is very accurate will allow you to identify if the valve works correctly. Many shops stock them. There’s a link towards the bottom the page on exactly how to perform that procedure. Otherwise, the article is intended to demonstrate how you can solve your problem.

Chevy Tahoe P0449 Definition

P0449 stands for a universal OBDII Trouble Code. This code can be used to indicate the same things regardless of the make and model of the vehicle (Tahoe) as long it was produced 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. If the system fails to function properly, fuel vapor will not be removed.

ECM (Engine Control Modul) detected a fault within the circuit controlling the vent to release fuel vapor. Soon, the service engine will follow this up.

Chevy Tahoe P0449 OBDII Code Symptoms

The P0449 code is usually not accompanied with any other symptoms than those listed. The smell of gas 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.

Tahoe P0449 Trouble code Causes

The P0449 code can be triggered by many factors in Chevy Tahoe. Below are the top problems that could trigger this code, along with an excellent video.

• 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 leading cause of 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).
• Trouble with Fuse or Wiring– 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. 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, it may erroneously throw P0449.

Chevy Tahoe Diagnostics - P0449

To diagnose the problem with your Chevy Tahoe's P0449, a mechanic will have a variety of tools at his/her disposal. The most commonly used methods to diagnose this code are:

• 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.
• 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.
• The mechanic will normally determine what problem codes are associated with P0449. Check out the EVAP System. It includes the purge valve and line as well as the canister.
• Monitor and check the pressure in your fuel tank.
• 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.

Have you got trouble with your computer? Here’s a Super technical video This is a great article on how to diagnose P0449.

Commonly Used P0449 Fixes

These are some of the most popular Tahoe P0449 solutions:

• Replacing the gas cap
• Replacing EVAP lines
• 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 test your gas tank.

You will need to solve the problem. We trust this helped. You can add any additional information by leaving a comment.

Do you consider P0449 to be a serious concern?

While P0449 is not going to cause the Tahoe’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.