What is the P0449 Code? Meanings, Causes and How Do I Fix Them?

A vehicle's emissions control system is complex and sophisticated. When you encounter the P0449 code, it could mean that there’s something malfunctioning with this delicate system. 

We will be discussing the P0449 code and its meaning in this guide. You will also find possible fixes that can get you on the road again without any warning lights. 

Definition of the code P0449

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

What is the P0449 Code?

Trouble code P0449 shows there’s a malfunction with the evaporative control (EVAP) system vent valve solenoid. It could also be caused by an incorrect amount of electrical resistance, or a component failing that needs to be replaced. 

The car’s EVAP system is responsible for capturing raw fuel that evaporates from the fuel system. It takes it from either the filler neck or fuel tank. The EVAP system stores and purges fuel vapors in the correct conditions, as determined by engine speed, load, temperature, and engine temperature. There’s a carbon canister that stores the fuel vapors and a vent valve that allows air into the system. 

P0449 Trouble code Symptoms

The P0449 code will usually not cause any major problems. You might get the Check Engine Light, but it’s rare that other symptoms would occur. Many people drive on, not realizing that something is amiss.

If there are problems, here’s the list of possible symptoms:

The P0449 code: Causes

P0449 could mean anything from a missing fuel cap, to much more complicated situations. These are some of the more common reasons to be aware:

Is the P0449 Code Really Serious?

Niedrig – It’s unlikely that the P0449 code is going to cause any trouble driving your vehicle. Although you may experience a decrease in fuel efficiency, overall your vehicle is likely to be fine.

However, it’s best to get the system checked as soon as you can. A failed emission test or inspection could result in a failure. 

Which Repairs can Fix the P0449 Cod?

It’s important that you do a proper diagnosis on the system to determine what’s wrong. Otherwise, you could be throwing parts at the problem, even when they aren’t necessary.

These are the top fixes for the P0449 error code.

• Gas cap to be replaced
• Replacing the EVAP line
• Resolve an issue with your wiring.
• Vent valve for charcoal canisters should be replaced
• ECU Update/Replace

Common errors in P0449 diagnosis

It’s very easy to overlook the most obvious problems and go right to something more complicated. In many cases, the EVAP system throws a trouble code simply because the gas cap isn’t tight or it’s broken.

You should first inspect the gas cap. It's possible to repair your code by simply replacing the gas cap. This will save you a lot of time and money. It is sometimes enough to tighten the cap or remove the problem codes.

Diagnostic Tools

How to diagnose P0449 Trouble code

The following steps would be taken if you were trying to troubleshoot the P0449 code as a professional mechanic. 

1. You might also want to check for any other trouble codes. If there are other codes present, it could help you figure out what’s wrong with the system.
2. The gas cap should be examined. You must first fix any damage or loose gas caps. 
3. Start an EVAP system leak check. To check for leakage, you will need to attach the vent tube to EVAP's vent control valve. Then use a smoke machine to pressure the system. You should look for the area that is leaking smoke. 
4. Verify that the connectors and wiring are in good condition. 
5. You might have to bring your car to a shop to get a professional diagnosis if you can't pinpoint the issue. 

Calculated Cost of Repair

Your costs will go down if you are able to fix the problem yourself. We will however outline the most common repairs and approximate labor costs for the P0449.

• Replace gas cap – $5-$25
• Replace EVAP line – $100-$400
• Replace charcoal canister vent valve – $10-$350
• Repair damaged wiring or electrical issue – $50-$500
• Update/replace ECU – $200-$1,200

Here are some mechanics tips about the P0449 code

High-end scanning tools can simplify the P0449 diagnosis. The basic scanners won’t reveal all of the information you need to get to the bottom of the problem. An EVAP self test procedure can be performed if your scanner supports advanced diagnostics. You can also command the EVAP solenoids and valves to turn on or off, helping you figure out what’s going wrong much easier.