Got an '06, SE Pathfinder, 135k miles periodically throwing a catalyst code. Doing due diligence, I checked the O2 sensors. The values that I'm seeing on my scanner aren't what I expect. If these were on my Chevy or Pontiac's, I'd say that I had 2 bad sensors with a 3rd one on the way out. It doesn't seem to bother the Pathfinder, getting around 15 mpg city and 19 hwy.
No other codes, just a cat efficiency code (Bank 1 if I remember right) that clears itself after a few days.
Here are the O2 values:
Bank 1 - S1 = .290-.310
Bank 1 - S2 = .07 - .79 (this one's range is what I would consider normal)
Bank 2 - S1 = .590-.610
Bank 2 - S2 = .25 - .66 (starting to fail?)
Based on past experience, when an O2 fails, they flat line. Neither B1S1 and B2S1 are flat line, but they don't move much off of it either. Slow bump up, flat for a while then drop down. Very slow movement. Much slower than what I've seen on other vehicles.
Can anyone definitively say what the acceptable ranges are for the O2 sensors on this 4.0 motor?