ABS is coming on? - Brake pedal judder?

Well. Using a torch on calipers is not a good idea. Seal may be leaking, is the red brake light on?
And if you followed the other guys advice, you may have damaged the sensor, grab an OHM meter, unplug the sensor from the harness and take a reading, I think yours should be about 2300 ohms, but I'll see if I can find the spec.

Can you put it on a code reader and find out what code it is showing? It may be a short or open code on the sensor (may be the plastic housing got cracked during procedure). I feel silly asking, but you did re-connect the ABS sensor back into the wiring harness right? (Assuming you disconnected it at any time during your previous maintenance). I'm at work right now and can't give you the restistance reading on my sensor.

Oh, and I agree with merlin2021. Heating a caliper is scetchy at best. In my younger days, I did that and ended up exploding the re-inforced rubber line that attaches to the caliper. Yeah. My head was in the wheel well when it happened. Very, very loud (ouch). :

Here's the scoop on whell speed sensors:
DTC C0221, DTC C0222, DTC C0223, DTC C0224, DTC C0225, DTC C0226, DTC C0227: WHEEL SPEED SENSOR CIRCUIT MALFUNCTION 1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK under DIAGNOSIS & TESTING. After performing diagnostic system check, go to next step. 2. Install scan tool. Turn ignition on. Drive vehicle at speeds greater than 20 MPH. Recheck DTCs. If DTC resets, go to next step. If DTC does not reset, problem is intermittent. 3. Raise and support vehicle. Disconnect wheel speed sensor harness connector. Using a DVOM, check resistance of wheel speed sensor. If resistance is 700-2000 ohms, go to next step. If resistance is not 700-2000 ohms, go to step 8. 4. Manually spin wheel as fast as possible. Using a DVOM, measure AC voltage generated by sensor as wheel spins. If voltage reading is greater than 100 mV, go to next step. If voltage reading is not greater than 100 mV, go to step 8. 5. Check for poor connections at wheel speed sensor harness connector. Repair as necessary. After repairs, go to step 10. If connections are okay, go to next step. 6. Disconnect wheel speed sensor harness connector. Check circuit for open, short to ground, short to voltage or shorted together. Repair as necessary. After repairs, go to step 10. If circuit is okay, go to next step. 7. Check for poor connections at EBCM harness connector. Repair as necessary. After repairs, go to step 10. If connections are okay, go to step 9. 8. Replace wheel speed sensor. After replacing sensor, go to step 10. 9. Replace EBCM. After replacing EBCM, go to next step. 10. Using scan tool, clear DTCs. Operate vehicle at speeds greater than 20 MPH. Recheck DTCs. If DTC resets, go to step 3. If DTC does not reset, system is okay.

You need to remove the front ABS sensors and clean the mounting surfaces with a wire brush. Re-install the sensors. If it still happens, you will have to replace the sensors.