I lost my button for my anti theft device on my 2000 chevy cavelier ,how can i override the theft device?
It's programmed into the computer modules, can't really be bypassed without replacing a bunch of modules AND reprogramming. I don't know what you mean by "lost your button" for the anti-theft, what you need to disarm it is the chipped master key. If you have no master key, you will have to buy a new chipped blank and reprogram the ATM to work with it, sometimes the owner's manual contains the procedure for that or you may have to take it to a dealer/locksmith.
Search Chevrolet Cavalier Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Chevrolet Cavalier Experts