The Nissan Path

ok guys can a scan tool be used on a 95 pathfinder
my truck is running rich any ideas would be a big help
i have new plugs wires cap and rotor new o2 sensor new coolant sensor but my temp gauge stays low

If you temperature gauge is staying low, my first thought would be that the thermostat is stuck open, not allowing the coolant to get hot enough. As far as a scan tool, your answer is "no." It uses Nissan's OBD I system, which works by using the red and green LED's on the ECM to tell you what self-diagnostic codes is stored. There was a 2-mode system and a 5-mode system, which is probably what you have. In the 5-mode, mode 3 was the self-diagnostic mode. For more on how to get the codes and what they mean, try this link:

https://www.troublecodes.net/nissan/

Thanks a lot that was really helpful
Didn’t think you could use a scan tool I was hoping to get lucky I found what looks like an Obd connection behind fuse box
Thanks again

There was a tool, but it wasn't really a scan tool. It was a Kent-Moore checker box that are pretty rare, today (I have one). It had a toggle switch, a readout to tell you what diagnostic mode you were in and red and green lights (like those on the ECM) and a beeper. It didn't really do anything that you can do at the ECM, itself, it just made it easier because you didn't have to remove or look under the passenger seat at the ECM to see the lights and turn the mode screw.