pstapler

This is somewhat of a follow-up to a previous post I made but I am getting a new OBD code so I figured I would make a new post. I recently replaced the Cam Position Sensor and Crank Position Sensor on the driver side and both downstream O2 sensors, all of which I was originally getting OBD codes for. I cleared the codes, unhooked the battery for a couple hours, reconnected the battery, drove the truck for 15 miles and the SES light comes back on. Now I am getting code P0420 (Two-way Catalyst System Bank 2).

Is this a result of the ECM relearning the proper mixtures after replacing the downstream O2 Sensors and will clear itself up after a while? Or is it another real problem?

TIA

jdgrotte

Get the code cleared, drive it again.
Light comes back on right away, like within a couple of miles, probably a bad O2 sensor (yes, I know you just replaced it, doesn't mean things aren't bad out of the store). Light takes awhile to come back on, probably a cat that's on it's way out....I say that because you had all of those other codes, which means that your timing and/or mixture was probably jacked up for awhile and you might've poisoned your cat and now it's poisoned/plugged/shot/gone...
And did you ever get the ECU updated?

__________________
Pointing out the obvious...

NALtech

Also does it smell like bad eggs?

supraholic

May be I posted this answer before, I had this same thing happend after the O2 sensors were changed out.. I had to take the truck to the dealer and had the ECU re-programmed (or Nissan called it, "firmware updates"). The SES light never came back on again. I do have an OBDII scanner. Just resetting the codes did not do the trick.

pstapler

I haven't noticed any foul oders.

Did the dealership charge you for the ECU reprogram or cover it under a recall or TSB?

NALtech

For a update that I do believe would be a recall/bulletin. The easy way to find out is to call the dealer and ask if you have any outstanding recall's on your pathfinder. Make sure you have your VIN number ready. You can also ask if there is any bulletins/campaigns for it for your described problems and what the cost is.

supraholic

Paid $170 ! at the stealership... I had no choice since the emission inspection was past due..