I have a punto 2000 model. Every now and again it revs like mad. Have been told its to do with the coolent temp sensor. If i just unplug it and run the car am i gonna cause problems?.

EM waring light will come on & fan will come on all the time.

p.s.your fault isn't with the temp sensor

Any ideas what the fault could be, if its not the temp sensor.

I'd say its a dodgey lambda sensor, but the only real way to tell is to get it on a diagnostics machine and see what fault code is being logged.