Theft System

Hello, I paid for a 2002 Malibue this summer and thought I got a really good deal (mileage 36,000 +). When I took it off the lot and drove it home, it had problems going up hills (little ones to). Well, I thought that it just needed some maintance done to it.......so far I have only paid a little over 50.00 to have it done. I need to have the plugs checked, to see if it needs new ones. The next thing that I noticed was that my car would not start . We did the 10 mintues wait and it worked to get it to start. Oh I forgot to mention that the Theft light came on while I was driving it, more than once after I had it for around 2 to 3 months. My car drives O.K. for a while, then when this Theft light comes on it drives like it could just stop working anytime (if it was the plugs there would not be a break in how it runs?). Without spending any money so far I have found out two things, 1. Be careful about who dose the work on my car. 2. Ask question no matter how stupid it may sound. I have been reading the messages on this problem and I have to say there is no way I am sending that much money on this. My machanic sent me to someone that works with alarm systems and he called GM and got the information that was needed to fix my ignation, first the plugs if that dose not fix it than I go back to the company that dose alarms for a living and only send over 200.00 to have it fixed.....

I have only one question why are some of the people having to upgrade
their information......is this needed... what questions should I be asking
before someone dose anything with my ignation (Theft system/lock)?

Need an answer before next month, it would help me out a lot....

Thanks, Malibue

P.S. I watch when my car is being worked on.........plus I have a very
honest machanic............gas felter was the one the factory put on it when it was made, so that can not be it, it was just changed.

Plugs have nothing to do with the security system!! This needs to be checked and diagnosed independently of any other problems.