remove padding from menu li element

Hello,
On my site Title I have a standard Joomla menu below the slider.

I modified the default.php of the menu module so that each tag has the T3 col classes:

class="col-xs-6 col-md-3 item-121 parent"

so they display in a grid. However the fourth item on each row, still applies the padding-right css so it does not line up with the edge of the slider above.

How can I remove this padding-right, yet still keep all items the same size and spacing?

Thanks

Lee