The OE Textar pads I use on my 126s and 123 fit perfectly, just a tad snug but they fit w/o shaving. It is sometimes necessary to take off some meat to install a pad but just a tiny bit. If the pad wear sensor is not making contact with the rotor I suppose you’ve not taken too much off. But you've decreased the service life of the pad and will need new ones sooner. What brand did you get from the dealer? Did you have the piston retracted correctly into the caliper?