Since I ordered an aftermarket sensor and it did not work I am now waiting for an ordered oem sensor. Do I reset the cel before I change the sensor or do I install the new sensor and see if the ecu recognizes it and then resets itself? This is on my e46 325i 2002 1998 328i 2002 325i 2006 X3
I would reset the CEL for sure, but it may not be convenient for you to do if you don't have your own scan tool. If that is the case, just replace it and then have the CEL turned off.