I have a 2000 4.0 with the single cat and 2 O2 sensors. I have looked at the official O2 sensor thread as well as various others. I've read to use the 97-99 upstream sensor NTK 23151. This sensor has been discontinued according to the NGK website. Does anyone know the correct upstream sensor part number? According to the NGK website, it looks like I need NTK 23122 but wanted to know if anyone else has recently changed this O2 sensor. If so, what did you use?
Kevin
Kevin