What is an exhaust gas recirculation (EGR) valve?
The EGR valve in your Toyota is fitted within the exhaust system and allows some of the gases produced during the combustion process to be re-burnt within the combustion chamber for a second and more effective time. This occurs when the correct engine operating conditions are met and, in turn, serves to reduce harmful emissions.
What does an EGR valve do?
The process of recirculating precise quantities of exhaust gases back into the combustion chamber has a number of advantages. In petrol engines, it helps to lower combustion temperatures and reduces the chance of spontaneous combustion, also known as knock. This allows the engine control unit (ECU) to dilute the air/fuel mixture and reduce petrol consumption.
In diesel engines, the role of the EGR valve is even more important. Routing exhaust gases back into the combustion chamber also lowers combustion temperatures, but the primary benefit is the reduced formation of nitrous oxide (NOx) particulates. In addition, the reappearance of spent exhaust gases within the combustion chamber enables the engine to neutralise these particulates through secondary burning.
Does the work of the EGR valve relate to the function of the particulate filter in diesel engines?
Yes, but indirectly. The neutralising of NOx soot within the combustion chamber reduces the quantity of this material heading into the diesel particulate filter (DPF) installed further down the exhaust system. This increases the time period between regeneration procedures and the service life of the DPF itself.
Why might an EGR valve fail?
Its location within the direct path of flowing exhaust gases means that soot can accumulate around the EGR valve and block its free movement. It is possible to mitigate this by ensuring the vehicle is regularly driven at sustained speeds above 40mph. Constant use of any vehicle in low-speed, urban environments with frequent stops will accelerate the amount of soot collecting around the EGR valve.
How can I tell if the EGR valve in my car is failing?
A failing EGR valve will affect the performance and economy of your engine, though it is likely that the ECU will notice the issue and alert the driver through a dashboard warning light before any physical symptoms are experienced. These symptoms may include rough idling, hesitance in acceleration and a loss in fuel economy.
What do I need to do if I see the engine check light illuminate?
Return the car to your main dealer to be checked. If the fault code displayed by the diagnostic equipment relates to exhaust gas recirculation, the likelihood is that the valve will need to be either cleaned or replaced. Cleaning is much cheaper than replacement, so it is prudent to react immediately to all warning lights.
My check engine light just came on because of the EGR valve. And of course it happened days before a trip from San Antonio to Houston and back. Can my car make it through the weekend? If I need to have the part replaced (and ordered) then I know that can’t happen in two days. Thanks!
Hi from the UK Alexandra. Unfortunately we are not able to diagnose your car over the internet. We suggest getting in touch with your local Toyota dealer so they can have a look. Thanks.
If the warning lights are coming on on my RAV4 while under warranty is this a warranty issue or will I be charged for cleaning? Is n’t there an issue with the size of the tube to the valve. My dealer is telling me I get the desiel from supermarkets and I do too many urban miles. The salesman didn’t explain any of this when we bought the car.
40,000’miles is not high for 3 years motoring what’s reasonable to expect from the dealer and warranty?
Hi Paul,
Thank you for your post. Our technical team have advised that this would be covered under warranty. If there is a genuine fault with the vehicle then this would be paid for under warranty. Hope this helps clarify. If you have any other questions please let us know.
Hi my 2011 reg avensis is giving out a lot of smoke from the exhaust only when in gear plus the economy on local journeys has gone very low. It’s not giving me any sign on the dash. What can be the problem
Hi there,
Thank you for your post. We have run this past our technical team and they have advised you visit your local Toyota centre. You can find your local centre here: https://www.toyota.co.uk/world-of-toyota/find-your-dealer.json. Hope this helps.
wow what is the point of asking question then you will just pass the query to your technical team. in my mind it would be more appropriate providing some possible conditions on why something happened giving a bettet Idea of what the problems may be instead of just passing it, your are just leaving the customer in the same condition when he asked you a question. at least with some may be answer he can ponder upon it then give the statement should you require a more professional help please do come visit our toyota dealer not will pass this on to our tech team wow!!!!!!!!!!
Hi Migiz, thanks for your comment. We always strive to provide the most helpful response to every question left here. It is not always possible for us to fully understand the issue a customer is having with his or her car without seeing it in person, which is why we sometimes recommend taking the car to a local Toyota dealer. All of the feedback left here is taken seriously and does get passed along to our technical team. Thanks.
Hi from a sunny South Africa! Just had my EGR valve replaced today in my 2012 Prado VX. Naturally i was was horrified when the engine check lights started flashing while i was some 100km from home. What is the chance of a recurrence of this valve giving up and then damage to the engine if i have to drive for a prolonged distance to the nearest dealer? Is this a fatal flaw in the 2012 VX or are these EGR valves meant to give up and how frequently? I do a lot of urban driving in the Joburg traffic. Thanks!
Hi Ash,
Thanks for getting in touch and we’re sorry to hear you’re having problems. Unfortunately, we are unable to comment on your vehicle as the repairs were made in South Africa. We would have to advise talking with Toyota South Africa. Many thanks.
Mid-December latest an orange warning lighted up on my dashboard. I was on the highway, and the car dramatically lost speed: dropped from 130kms to 80kms in a few seconds. I left the highway and went with the car to the dealer/garage.
After examination it went out that the EGR valve was defective and needed to be replaced. According to the dealer, the part was available end of January. In the meantime, as they told me, I was allowed to use my car. I really need it to go to work. It is really not pleasant or reassuring to drive with it. The fan is constantly turning (motor overheated??), the car “swallows” gasoline as if it’s water, the driving not at all efficient (it is almost a tractor when you have to change gear) and the driving is not fluid. It’s really not a pleasure to use it. Now, the worst is coming… the lead time is not end of January anymore, but “unknown”!! Latest news: it can take “several weeks”! As I heard I am not the only one. It seems to be a manufacturing problem. In this area only, almost 400 car owners have the same defect.. I am not at all happy with the Toyota service, because of a problem that is not my fault at all I need to drive this car another XX days.. with a scary hart, because there’s no other solution. If I want a replacement car, it costs 36€ per day, and amount that I cannot afford
Hi Betsy,
Are you a UK based customer? Many thanks. 🙂
Good morning Ella,
No, I am from Belgium, but the car was produced in England.
Hi Betsy,
Have you taken this to a Toyota dealer in Belgium?
Hi Ella, yes of course. As written in my first message. They told me that I could drive with it till the day that this part arrives in the garage. I don’t have another choice then to do so because they ask 3euro pet day for a replacement car and they don’t know how many weeks before that this part arrives. I drive every day to my work with a very scary heart…
Hi Betsy,
Apologies, we can see that you’ve been to a dealer in Belgium. Due to your location, we would have to suggest contacting Toyota Belgium to see if they can assist. You can find all contact details here: https://nl.toyota.be/forms/forms.json?tab=pane-contact. We hope this issue can be resolved via Toyota Belgium’s customer relations team.
@ELLA: Dealer: Toyota City Zaventem. You can find it on the Internet. It’s a very big and important dealer in this area. Not a small garage.
Hi Betsy,
Please see our reply to your previous comment. Many thanks.