If your feeling modulating under braking, then its a good possibility that you got a warped rotor, and if you hyper extended the caliper without the brakes being metal to metal, then your rotor should be replaced.

ABS can cause the brake pedal to modulate too, its actually how it works, but you should never feel it. Pull the rotor and have it measured and you might be able to turn the warp out if its not to bad.

I would also suggest bleeding both calipers to make sure there is no air in the system when you get done. Typically the rule is you start with the caliper farthest from the master cylinder. Check all your brake lines for fray/chaffing too.

If the brakes are dragging after a caliper and rotor replacement, its a sign you got a bad rubber line. Over time they absorb fluid and can swell shut not allowing the pressure to release from the caliper.

Good Luck with it.