There are a few things that could be causing this:
I believe the yScale will scale the image down but not change the value when later used to set the physics body size. (essentially the physics body = original image size)
I do not see a contactBitMask which will allow you to check when your (flappy felipe or mario?) comes in contact with the pipe.
To fix this try:
Draw a rectangle using the same variables you currently use and color it black. This will show you where the physics body is being drawn.
set them to have a contact event and then log their contact