Hello, I don't think the egr valve is the fault in your case.
Most likely is a faulty coolant temperature sensor or poorly fitting connector at the sensor.
Other possible causes are a dirty throttle body. This can be cleaned with a soft lint free rag and brake fluid.
Thanks for the prompt reply is this something I can do or would I have to take it to the garage? Also why didn't this show up on the diagnostic testing as the engine was cold when they did that? Are you based in the Uk as the time this was sent was the early hours of the morning?
Yes I am based in the UK.
I would advise a garage doing it as you may have to replace part of the wiring. If done incorrectly then you could cause more problems than you fix.
The garage should also use the scan tool to check the live readings from the engine sensors as they can still be faulty or give poor readings but not generate a fault code.