Hi I've got a 2002 1.4 petrol fiesta that's reving at 3000 rpm while ticking over I had a eml said lambda sensors they've been changed and no light on now but still over reving any ideas tia 

If I had to guess, you have a vacuum leak, make sure there isn't any perished or disconnected vacuum hoses in the engine bay, and make sure there isn't a sucking sound from the brake booster.

Also make sure your throttle is actually fully returning to idle

9 hours ago, Neb_engineer said:

Also make sure your throttle is actually fully returning to idle

That👍

Check the oil breather hose under the manifold.  They split fairly often and suck unmetered air into the manifold.

Thank you I'll check now 👍

Hi mate I had the same problem not long ago for me it was the crank air intake hose you could check that cost around £6 off eBay 

 

As has been touched on an unmetered air leak can easily cause this. Plug an OBD reader in and monitor the short- and long-term fuel trims. If these are persistently high-positive (say, >+10%) then that gives a strong indication that this is what the issue is because more fuel is needing to be added to compensate.