The EGR valves (exhaust gas recirculation) are designed to stop nitrogen oxide pollution. They have to work right or your check engine light will come on and you can fail an emissions test. Sometimes, the EGR valves can break and stick wide open. Then, it’ll suck so much air that the engine will idle poorly and run badly because there would be more air than fuel mixture in the combustion chamber.
The hot exhaust gas comes out of the engine and some of it goes into the EGR valve. When the EGR valve opens up, it sends a hot exhaust gas back into the intake manifold, so which sends already-burned gas into the engine. So, the engine temperature
Over time, the carbon builds up and will clog the EGR valve
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How To Clean an EGR Valve Without Removing It



Over time, the EGR valve gets dirty. The carbon builds on the walls of the EGR valve and it can cause
1. Gather the needed cleaning supplies


In order to clean your EGR valve, you will need to have a clean microfiber towel, an EGR valve cleaner, and latex gloves. The EGR valve cleaner is a corrosive product, so it’s best if you wear gloves while cleaning the EGR valve. I personally use the LIQUI MOLY EGR valve cleaner (check the price on amazon.com
2. Locate the EGR Valve


Different vehicles will have their EGR valve in different places. The EGR valve is attached to the intake manifold. Usually, the EGR valve is located where on the backside of the engine. If you do not have direct access to the EGR valve without removing a lot of parts, you can find the nearest access to the EGR valve. On some vehicles, the closes access point to the EGR valve is through the turbo.
3. Gain access to the EGR Valve



Gain access to the EGR valve by removing the cover. Be very careful not to lose any screws or clamps. Your EGR valve might not look like the one shown in the photo, but I am sure that it won’t be crystal clear.
4. Start the vehicle and rev it to 2000 RPMs


Start your vehicle and wait for it to reach the normal operating temperature. You will need someone to sit in the car and keep the RPMs in 2000. The sound of the engine will change because as you spray the EGR valve cleaner, the air-to-fuel mixture ratio will be different.
5. Spray half of the cleaning solution (250ml)


The EGR valve solution that I use comes in a 500ml can. Ideally, I use half of the can only. Make sure to spray little by little. You don’t want to overwhelm the engine. Short 1 second sprays will do the job just fine. Wipe the EGR valve and surrounding area with a microfiber towel.
6. Reinstall the EGR valve cover
Turn off the car and wait for the engine to cool down and then reinstall the EGR valve
7. Scan the vehicle for error codes


At this point, the check engine light should turn
Most Common Signs That Your EGR Valve Needs Cleaning
There are 2 most common signs that your EGR valve needs cleaning. These signs are perfect for people that don’t have scanning tools. If you do have a scanning tool, you can go ahead and run diagnostics. The scanning tool will show any EGR-related error codes if the valve needs cleaning or replacing. Here are the most common signs that your EGR valve
1. Rough Idle
The function of the EGR valve is to reduce emission gases exhausted from the vehicle. The emission gas is recirculated back to the engine through the intake manifold to be re-burned in the combustion chamber. Normally, when the EGR valve is clogged, rough idle
2. EGR Valve Stuck Closed
Usually, this is caused by a blockage and buildup of carbons. If the EGR valve is clogged, there is also a good chance the intake manifold is full of carbon as well. Some of the symptoms of a stuck closed EGR valve
What Is The Best EGR Valve Cleaner


Liqui Moly is a German company that produces a lot of car cleaning products. One of them is the EGR valve cleaning product. I personally have used this product for cleaning my EGR valve without removing