If the sensor hasn't worn through and tripped the light you can reuse it, but they get brittle from the heat over time. Best practice is to change them. They aren't expensive. Recommend you use OE sensors and not no name clones.

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue