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EGR faults
EGR fault code? It's not always the valve.
EGR codes are some of the most misread faults. We test before anything is replaced, so you don't pay for a valve you didn't need.
What the EGR valve does
The EGR valve feeds a little exhaust gas back into the engine to cut emissions. Over time it can clog with soot or stick. But an EGR code can also be caused by a boost leak, a sensor or wiring, which is why so many valves get replaced for nothing.
Signs to look out for
- Engine management light on
- Rough idle or the engine stalling
- Loss of power or flat spots
- Black smoke
- EGR fault codes such as P0401 or P0403
Usually fine to drive gently. Get it checked soon, because a sticking EGR valve can lead to DPF problems.
What usually causes it
- Soot build-upThe valve clogs and sticks open or shut.
- Boost or air leaksSplit pipes that make the system look like an EGR fault.
- Sensors and wiringBad signals to or from the valve.
- EGR coolerBlocked or leaking coolers on some engines.
Find the cause first
How we fix it
- Read codes and dataWe see what the ECU is asking the valve to do and what it actually does.
- Test the valve and pipesIncluding a smoke test for leaks.
- Fix the real causeClean, repair or replace only what has failed.
Your options
Recommended
Book us
Bring it to our HQ at Mallory Park. You get a price before any work starts.
Book a check →Fix it yourself?
Best left to us
This needs hands-on testing, so it is best we see the car.
Common questions
Do you remove or blank EGR valves?
No. It is illegal on UK roads. We repair the system so it works as it should.
Can an EGR valve be cleaned?
Often, yes. If cleaning will fix it, we'll tell you. It's usually cheaper than a new valve.
Why did my new EGR valve not fix it?
Because the valve may not have been the problem. A boost leak, sensor or wiring fault can set the same code.
Do you work on vans?
Yes, cars and vans of all makes.