Hopefully i can help..
Are there any other warnings on the dash that have come on prior or after this fault ocurred?
What sort of mileage does the car have?
And have you had any recent work carried out on the vehicle?
Hi..there thanks for your reply..
Ok.. If the engine is only restricted to a certain rpm and speed wise as you describe it quite possible the vehicle is in limp mode - sort of ecu safety programme that restricts the car until it been diagnosed on a machine as in regards XXXXX XXXXX ever the ecu itself has picked up as faulty on the engine management sensors or emissions system - so if nothing visually can be spotted around the engine bay as such in regards XXXXX XXXXX loose pipe work intake.vaccum/fuel leaks basically go over the engine and check everything is fully connected and not loose - you need to check for any possible restrictions in the intake system/airfilter as such aswell - then the diagnostic route would need to be done..there are other possible things that could cause this from a restriction in the fuelling system ie: possible blocked fuel filter "certainly maybe try that as per changing" or fuel pressure issue - or you the exhaust system maybe restricted causing alot of back pressure this would certainly cause a massive power loss issue and the only way to verify that if all else has been ruled out above is to disconnect the exhaust system from the front manifold - have the system supported under the car or remove totally.and drive the car or see if engine power is restored - .if it does then you'll know exactly what the issue is and basically narrow down which part of the exhaust systems at fault....However if you have bought this vehicle from local car dealer/trader very recently and there is a warranty on it that you know of then it would worth contacting them in regards XXXXX XXXXX as such..of course this wouldnt apply if the car was sold as seen or privately..so as above there are a few causes for the issue you describe..I do hope this helps