how can i fix hooter and immobiliser,opel,2006 corsa sport 1.4i?

by the hooter, I assume you mean the horn. That is an MOT failure so you need to get it fixed. Its usually located under the car at the front. Check that there is a wire going and out. If, say the wires are frayed then its a cheap fix. If not its garage time. The immobilizer I would get a car electrician to look at, if changing the battery and making sure the buttons are free in the unit does not work.

Mike
May 2010