How to make a 2x2 piston door!

First you will need to start off with 12 red stone, 4 sticky pistons, 4 block of your choice, 2 red stone torches, 4 pressure plates, and a stack of any block you wish.

Start by digging a 2x3 whole 2 blocks deep. Then fill the bottom with red stone.

Now fill the blocks with the desired block of your choice.

Place the sticky pistons as shown in this photo.

Place a piece of red stone on top of this block as shown in the picture. Do this on both sides.

Add pressure plates. Ta Daa!