P0404 Code: Exhaust Gas Recirculation Circuit Range/Performance Problem

If you’re getting a P0404 code on your scan tool, here’s a quick but detailed guide on what it means, what causes it, and how it can be fixed.

What Does the P0404 Code Mean?

Diagnostic Trouble Code (DTC) P0404 stands for Exhaust Gas Recirculation Circuit Range/Performance Problem. It is a generic OBD trouble code that activates if the powertrain control module (PCM) detects erratic Exhaust Gas Recirculation (EGR) valve performance.

It could mean that your EGR valve isn’t doing what it’s supposed to do in specified parameters such as being fully open when it should only be partially open. This can be bad as, for example, too much exhaust gas can make it difficult for the engine to idle.

The EGR system redirects exhaust gas back into the engine to lower the temperature in the cylinder and lessen nitrogen oxide (NOx) emissions. This system uses a valve to regulate the flow of exhaust coming back into the engine.

The valve is monitored by the PCM, and sends information on whether it’s open, closed, or partially closed.

An in-depth understanding of the EGR system could help you fix the issue if you’re planning a DIY approach. You can read our advanced, technical discussion about the EGR system. Otherwise, continue reading below for the possible causes of P0404.

P0404 on Some Chrysler Vehicles

Code P0404 may appear on some Chrysler vehicles. On a 2005 Chrysler Town & Country 3.3L V6, for example, this DTC is set when “the EGR flow or valve movement is not what is expected.”

The code may appear in a 2005 Chrysler Town & Country 3.3L V6 because of the following conditions:

• Good trip equal to zero
• High resistance in 5 volt supply
• EGR solenoid control ckt
• Intermittent condition
• EGR sensor signal circuit open
• EGR sensor signal circuit shorted to ground
• Sensor ground circuit open
• EGR assembly (ground)
• Issue with PCM

For this specific vehicle, it is recommended to diagnose all other EGR DTC(s) first before continuing with any test related to P0404 code.

What are the Possible Causes of the P0404 Code?

Code P0404 usually indicates that there is a carbon build-up somewhere in the lines, or on other occasions, a bad EGR valve.

There isn’t really any way to prevent carbon build-up as it can naturally happen over time, but if you are getting this fault prematurely, here are the possible causes as to why:

• A short in the 5V reference circuit
• Open ground circuit
• PCM-controlled voltage circuit short
• Faulty PCM
• Faulty EGR valve
• Malfunctioning EGR sensor

What are the Common Symptoms of the P0404 Code?

It’s possible to find no observable symptoms of a P0404 code aside from a check engine light. However, EGR valves are known to fail due to poor maintenance, which as previously mentioned, results in carbon build-up. This can block the valve and prevent it from opening or closing completely.

If the valve starts to fail, the engine may begin to experience performance issues like:

• Rough idling
• Poor fuel economy
• Increased NOx emissions

Keep in mind that increased NOx emissions may lead to a failed emissions test. The engine is also at risk of higher combustion temperature, which aside from causing bad mileage, can also cause the engine to overheat.

The symptoms mentioned above can be the result of another underlying issue. Like any other OBD-II trouble code, you’ll need to rule out multiple causes before you can actually get to the main problem and determine the proper fix.

How to Diagnose the P0404 Code

Although P0404 is considered a generic code, the specific diagnosis steps may vary depending on the make and model of the vehicle.

To give you an idea about the P0404 code and how to diagnose it, check out these videos:

How to Fix the P0404 Code

Troubleshooting a P0404 code isn’t going to be an easy task. But if you’re up for the challenge, then feel free to grab your toolbox and try these common repairs:

Fix EGR Valve

In most cases, vehicles will throw a P0404 code because of a stuck valve. After locating your vehicle’s EGR valve, use a scan tool to control it. If it doesn’t completely open or close all the way, then it’s likely stuck or blocked by carbon build-up. You’ll have to clean your EGR valve or replace it with a new one.

Replace Any Damaged Parts

If your EGR valve isn’t the problem, then you might need to inspect other parts of the engine management system. Check your ground circuit for any shorted wiring or broken connectors. If your wires all look good, you can also try replacing your EGR sensor or updating the PCM.

Keep in mind that these common repairs won’t work for every vehicle. What gets rid of a P0404 code on a Chrysler might not work on a P0404 on a Honda. If none of these fixes work for you, then it’s time to book an appointment with a trusted mechanic.

Where to Get a New EGR Valve for Your Vehicle

The symptoms listed above often lead to hefty repair bills at the auto shop if you leave them unresolved. If a faulty EGR valve is the culprit, it’s best to avoid driving until you’ve replaced it. Luckily, CarParts.com has high-quality pieces you can choose from.

One thing we guarantee is fit and quality. With our website’s vehicle selector, you can view the valves that fit your ride. And to ensure you get a part that performs like your stock part, our industry professionals handpicked our products from top aftermarket brands.

If you have any questions, don’t hesitate to contact our round-the-clock customer service team. Get your new EGR valve in as fast as two business days after ordering it. Take advantage of our unbeatable deals on replacement parts. Get the best value for your money when you shop at CarParts.com.

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Products Mentioned in this Guide

EGR Valve EGR Pressure Feedback Sensor