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Toyota EGR valve: understanding exhaust gas recirculation valves

By Toyota Blog

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.

134 comments

  1. Yesterday my Auris 2012 started to shake and loud noise coming from left side (electric motor I guess), weird thing is no light or warning came on dashboard, was difficult to drive at low speed. Took it to garage today and the guy knew straight away without even lifting the bonnet that EGR is blocked. After cleaning the manifold and valve the car is back to normal, but was told I have to do the same thing again after 5000 miles because I only use the car for small journey at low speed. Did Toyota make Auris only for motorway drivers?

    Reply

    1. Hi,

      We’re glad you’re back on the road. Constant use of any vehicle in low-speed environments with frequent stops will accelerate the amount of soot collecting around the EGR valve. 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. Thanks.

      Reply

  2. Thanks for coming back to me.
    SB1BN76L50E012382
    The diagnosis had from Toyota Liverpool this morning was: ” POOBD stored in engine ecu- fault caused by carbon build up in manifold/egr/cooler etc. “

    Reply

    1. Thank you for this information. We will send you an email now and if you could please respond with contact details such as full name and phone number we will open a case with our customer relations team to investigate this further.

      Thanks.

      Reply

  3. Hi I have a Toyota Avensis 2015 and having the same problem. Check parking brake system with Engine management light on. Just done 80000 miles. Booked with Toyota to have a look in couple of weeks. Long journeys are fine it comes up on short journeys only. Fuel economy has gone down and car does not pick up quickly due to limp mode.

    Just came to know that there is a free EGR Valve recall on Toyota avensis as it is a common problem. Can someone please confirm this as it looks to be EGR valve problem.

    Reply

  4. Quick update. I found a code P042E with my basic OBDII Scanner, it means that the powertrain control module (PCM) has detected a problem with the exhaust gas recirculation (EGR) valve control system.

    Luckily my 2015 Toyota Avensis had a recall on EGR valve. Today Toyota has replaced the EGR valve as part of recall and no warranty required for this as this is recall.

    Engine light and Check parking brake light is gone now :).

    So if you have this error please check if you have a recall for EGR valve and get it done free, if not than get the EGR valve changed at your cost as this is not covered under warranty.

    Hopefully this helps everyone battling with this problem.

    Reply

  5. I have Toyota Noah engine model TA-AZR60G with high fuel consumption running 6 km/Ltr..EGR valve might be the problem.Tried to replace Throttle body,Fuel Pump,Spark plug but no improvement

    Reply

  6. I have a Toyota land cruiser 2010 diesel engine 1 VD series, I changed injectors, and is smocking badly ,black smock. What can be the problem?

    Reply

    2. Hi I have Toyota auris hybrid 2015 Slightly shaking engine and rattling noise on acceleration,it happens when the car is hot and especially when the battery level is very low ,I guess is when as more load .
      If I accelerate and keep it steady at 20mph I can feel a constant vibration but goes away once accelerating more….like if you’re driving on a rippled surface ….that is only when engine is on , doesn’t happen on electric only.
      The noise it sound like a tapping coming from the engine when slowly accelerating from 0 that goes away as soon I give more gas ,is annoying wile in the traffic.
      Ideas,? Can the sparks plugs be the problem?they been changed at 80k and EGR valve And the car done now 117k …..,I cleaned the egv pipe And the manifield but problem still there.
      Like I said is only when the engine is up to running temperature.
      Not sure but the noise may be coming from the tranx?
      Thanx

      Reply

      1. Hi Ebo,

        Thanks for getting in touch. We’re sorry to hear about the issue you’re experiencing. Without assessing the car ourselves, we can’t accurately suggest what may be causing this. Therefore, we would recommend contacting your nearest Toyota centre to discuss this further. They are best equipped to run a diagnosis and make any necessary recommendations. You can find the contact details for your nearest dealer here: https://www.toyota.co.uk/dealers/#/iframe/https%3A%2F%2Fforms.toyota.co.uk%2Ffind-a-dealer

        Thanks.

  7. Hi I have Toyota auris hybrid 2015 shaking engine and rattling noise on acceleration,it happens when the car is hot and especially when the battery level is very low ,I guess is when as more load .
    If I accelerate and keep it steady at 20mph I can feel a constant vibration but goes away once accelerating more….like if you’re driving on a rippled surface ….that is only when engine is on , doesn’t happen on electric only.
    The noise it sound like a tapping coming from the engine when slowly accelerating from 0 that goes away as soon I give more gas ,is annoying wile in the traffic.
    Ideas,? Can the sparks plugs be the problem?they been changed 25k ago and EGR valve…..,I cleaned the Mansfield and the EGR pipe recently but problem still there.
    Like I said is only when the engine is up to running temperature.
    Not sure but the noise may be coming from the tranx?
    Thanks

    Reply

    2. Hi Ebo, I have a Toyota Auris Hybrid 2014 and I have exactly the same problem, most people on different websites and a mechanic told me is the EGR valve.
      I had my catalytic converter stolen and I replaced it with aftermarket one, I don’t know if this can be the reason or not?? Do you have the original catalytic converter or you also have changed it? I am trying to understand where the problem comes from.
      Thanks

      Reply

  8. Sadly my Egr on my iQ is blocked. Toyota dealer wants more than the car is worth to fit a new one even though many were done as a courtesy as it was a design fault in early models. I’m going to have to give up on it… I thought it would be better made. I’ve had 5 Toyotas and this will be the last one.

    Reply

    1. Hi James,

      Thanks for getting in touch.
      We’re really sorry to hear about the issue you’re having with your iQ and that you are unhappy with your experience with us.
      If you would like to raise this further, we would recommend contacting our Customer Relations team as they are best placed to explore your situation further.
      You can contact them via this link: https://www.toyota.co.uk/contact-us/email-us

      Thanks.

      Reply

  9. Hey. My lc200 2013. I got some petrol from gallon i had. My fuel ended up.. And when drove a km my car started missing up. And soon after if i press acceleration full hard. My rpm gets stuck at 3. And car just loses power. Soon i lift my feet up and press it very slowly and gently, it goes well. But rpm dosent cross 3.
    When i start in the morning. Nd give full throttle, it does well. Soon engine get heat up. My rpm comes back.to 3.
    To fix this issue. I cleaned my fuel tank. Changed fuel pump, fuel filter,and all other things to clean the fuel line. But problem was still there. Got my catalytic converter cleaned, changed spark plugs, cleaned oxygen sensors and mass air flow sensor. But problem is still there. Added up mean while fuel injector cleaners and good high octane, but no luck.
    Last night my mac found out there is a leakage on main air vacuum head. Top body of engine. We managed to fix that. Now rpm goes upto 4. Nd no more. Can u please help me on this…

    Now the only thing left is EGR value and Throttle position sensor….. suggest pls.

    Reply

    1. Hi Ali,
      Thanks for getting in touch with us.
      We would recommend contacting the Toyota distributor in your region for further help with your query.
      Thanks.

      Reply

  10. I have a 2008 Toyota Yaris d4d we believe the egr valve is failing and tbh the only thing wrong is fuel I seem to be using a lot I mean I do about 350 miles a week atm due to work I’ve had an engine light on for months but the car has never failed I want to take the egr valve out for a clean but am unsure we’re it’s located in my vechile

    Reply

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