you can buy a whole new reconditioned unit from theses people if your steering is fixed in place its the same price as the adjustable one. they even come with a longer warranty than the vauxhall ones does. they only want £175 for theses

http://www.bba-reman.com/catalogue/DetailedProduct.aspx?DetailedProduct=2093

but you gotta send your old unit back to them which they pay for the postage. cant remember if you gotta pay postage but it prob only be like £20 quid or so. but i never had a problem with mine. i have also know a few people who have used them for the same part and never had a problem but you could just go to the scrapyard and get a new torque sensor as it is that what breaks down. but some people just adjust the torque sensor which is the most dangerous thing to do as when you driving the steering can lock up when turning a corner thats why they clue the torque sensors so you just need to unbolt your old one and bolt in the one you get and it all be set up. hope this helps

 

You can repair corsa c with heavy steering to one side. My m8 got his repaired and only cost him £60. He took it here

http://www.car-diagnostics.uk.com/Home.html

 

About £300 for one with a warranty.
the corsa normally goes light one way or pulls

 

I have a corsa 1.3cdti and the steering is very light you can turn it with your little finger. if the steering goes ur looking at 500+ to fix does it come with a warrenty?