I was changing my speakers and as i put the door on I was double checking all my buttons. The lock pin didn't seem like it was going up all the way when I was hitting the unlock button, I pulled on the inside door handle and hear a pop. Now when the car is locked that door can still be opened just like if it was unlocked. I've taken the door off and checked everything I can find but am still baffled. Help please?

 

Maybe the latch assembly went bad.

 

+1 on the latch assembly. When they break, they do all sorts of weird stuff.

 

There's a small plastic piece in the door latch assembly that broke off so it doesn't allow the door to lock but just appear locked.

You'll need to replace the whole assembly. They can be pricey, so I recommend you pull one from a junkyard. It's a pretty simple job.