Coming home from work last night the car wouldn't drop below 1800 rpm with no throttle and when put in neutral or park it climbed to over 3k rpm making selecting a gear horrible so on the journey home I kept it in gear. Any ideas? TIA

The car is drive by wire, meaning the throttle pedal is an electronic volume control (for want of a better description). These can start to play up, and may need replacing. Another thing could be the throttle body requiring a clean.

How remiss of me I never did update this, turns out my car does not have a fly by wire throttle its old fashioned cable and the cable got stuck over a pulley and so wouldn't return. Cable re-seated, cleaned and lubed and no reoccurrence since.