They are cheap, and some kits include them anyway, so I don't bother with r&r-ing the old sensors...and yes, from experience, improper install can set off the light easily...

__________________
2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car