My Punto failed to get an emmissions test cause they could not hold a steady fast idle speed between 2500 and 3000 rpm!!!
Any suggestions

Depends what sort of Punto it is - the 16v 1.2's have an electronic throttle that accelerates the car automatically. As you hold the accelerator in one place, the revs just keep on building! This effect is much stronger when the car's not in city mode - supposed to feel more sporty according to the manual. Try switching on the City mode and holding the revs steady yourself before going for a re-test.

My Punto is the 8 valve variety, 1.2 ELX

Hi Fergus, dont know if its the same problem as I had on my Mk1 75SX, but after many visits to the local Fiat garage, they diagnosed the problem to be a faulty Lambda Sensor. I could sit stationary in my car, and try and hold the revs to 2000, but the car would vary between 2000 and 2500 every 3 or 4 seconds. I would also find a slight hesitation every 3 to 6 seconds whilst driving on any major road. Hope this helps. Fiat charged £55 ish for the sensor (+fitting) but other suppliers prices varied between £50 & £75 without fitting! Sometimes Fiat are well priced. Good luck!