How to fix my skoda octavia 2001 1.8 20v turbo vrs?

When i prepare to stop, from any gear, as i put my foot on the clutch the rev counter will only drop to around 1300rmp's. While coasting to a stop with the clutch then released the rev counter will not return to its idle of around 800rpm until i have completely stopped!
When crawling along in 1st gear (with my foot off the acelerator) with revs at around 1300-1500rpm i can feel the car 'running on' as if i can cruise control, rather than gradulaly slowing its speed is constant! very frustrating.

I have just had the a coil replaced and new spark plugs.

can anyone help, ps it does idle higher than it used to (before the spark plugs and coil replacement.

matt