Just had my catalytic convertor on '01 Maxima changed after pulling P0420 code. Asked if they had changed O2 sensor as well, after having read numerous things saying this is recommended. They said No as it did not pull that code and they do not change things that do not NEED to be changed. Within 100 miles of leaving shop, SES light came on. Took it to Auto Zone to have ECM read before progressing back to shop, Guess what came up? The actual printout says something to the effect of "input voltage from O2 sensor and Bank2 is too high for current operating conditions". Took car to shop, they ordered part and I overheard him saying it was the sensor "with the white sleeve and the long plug." In trying to price the part myself from Auto Zone, they couldn't tell which sensor it actually was. Don't really know how they intend to sell me a part when they don't know what it is, but thought someone here might be able to help with the identification so that my friend can change the part after having spent way too much already at the shop. They were very considerate in offering to install it with no labor charge, but didn't offer to throw the part in at their cost. Any help is greatly appreciated.