2001 Pathfinder engine codes

[LMH1974]

Have a 2001 pathfinder that is throwing codes 0301, 0138, 0139 and 0158

Any help on the severity or cost to fix would be greatly appreciated.

[centralcoaster33]

Hello and welcome to NICO Club! We have available the FSM for your car (I don't know if you have 2001 or 2001.5):
http://www.nicoclub.com/archives/nissan ... nuals.html

The EC chapter will have a break down of codes and how to deal with each one.
P0138 = Heated O2 sensor 2 (furthest from engine)
P0139 = Heated O2 sensor 2 (furthest from engine)
P0158 = Heated O2 sensor 2 (furthest from engine)
P0301 = Cylinder Misfire (1st cylinder I think)

So, at least replace your secondary oxygen sensor to start. It might be a good time to replace your spark plugs while you're at it. Drive a while and see if codes clear. I don't recommend clearing them on your own. Let the car computer clear them.

Please let us know how it goes!