P0139 and P1147...
 

It also shows P0021 all of the sudden but im going to reset and see if that makes it go away(i got stuck in a patch of ice in my friends driveway thinking that could have triggered it somehow)

anyway rockland nissan and a local mechanic said that this code requires 2 sensors to be replaced and an ecu reprogram. My issue is that these codes point to an issue on the same sensor meaning only one is bad...but they say two...am I missing something or are both of these guys messin with me. Also how important is it for the ecu reprogram. Can i get away with just using the pedal dance to reset it?? Thanks guys

I just replaced the bank 1 rear O2 (same codes you got) and the SES light only came back on once, at 168 miles, reset it and I haven't had those codes since and it has been about 17,000 miles. Start with the O2 you need to replace first and see if that takes care of the codes before you change both.

If you were on ice and bumped the rev limiter, sometimes that will trigger the P0021/0011 or the corresponding camshaft position sensor codes. Clearing the code is usually enough.

okay sounds good thanks for the help scott. I reset the cel and it came back on with no code for the camshaft sensor anymore.

My car had that too. The reason your techs told you to replace both rear sensors is because there is a tsb (technical service bulletin) on those two sensors. Those sensors go bad all the time and Nissan created a reflash to prevent them from going bad premature. The reflash is probably used to cut down on how much the heater circuit turns on and off

Scottwax,

I got these two same codes myself now (P0139 and P1147)...how difficult was it for you to replace the O2 sensor yourself? Any idea what the part is worth? Also, did you have to reprogram the ECU yourself or what? Thanks in advance!

The O2 isn't that hard to replace, but routing the wire is a little tough. All I did was the O2, I didn't have the computer reflashed-and unless you have a Consult II and the appropriate software, only the dealer can do the reprogram.

O2s can cost from the $60 range for a universal part to $140 for OEM.

Thanks for the reply Scott, I must have misunderstood about the need to reprogram the ECM after swapping out the O2 Sensor. It sounds like you don't have to do that, you just replace the sensor and away you go? Thanks!