I have the wiring OK and it works fine when only the module is plugged to the arduino.
The problem started when i plugged leds and waterpumps in the arduino digital pins to respond to the capacitive sensor inputs. when other things are conected the arduino does not find the MPR121.
i thought something was wrong with the mpr121 and i unplugged everything that wasn't related to the module and it worked again
Impossible to say without a schematic and code from you.
Start with only the touch sensor connected and test that it still works. Then add the other components one at a time. Test that the touch sensors work, after each new component is added. Which one is causing the problem? Once you think you know, remove all the other components except that one and test again to confirm that component alone is causing the problem.
You should know that you cannot connect a water pump directly to the Arduino. You should use a relay module or a MOSFET circuit between the Arduino pin and the pump.
