can i install an sub and an amp without changing my stock stereo deck??

 

Absolutely Yes!...........All you need is a line level converter. an amp, and a sub. Please note that the factory head unit is WAY under powered and will have a difficult time keeping up with an amp and sub, so it would be advisable to buy a 4 channel amp and amplify the door speakers as well as the sub...............Good luck!

 

Check out the electronis forum. There's all sorts of info over there.