2003 Toyota Matrix the factory car alarm won't quit working after I repla ?

Your key may need reprogramming in the car.

https://www.youtube.com/watch?v=2dNCOltF7kk

http://blog.dawouds.com/2010/07/matrix-program-keyless-entry-remote-fob.html

http://www.chadspictures.com/automotive/How-To-Program-Toyota-Key-Fob/

Found within 30 seconds. Plenty more out there
February 2016