p0139

i have this code on my 2001 nissan 3.0, is it true that you have to do a tune up first to avoid that code to come back?
and then replace the o2 sensor?
thank you for taking your time to answer my question

P0139 refers to the Bank 1, sensor 2 O2 sensor's response is slow. Generally replacing the o2 sensor fixes it. Make sure you don't have any exhaust leaks, too as that could cause a slow response. A tune up wouldn't be a bad idea, but wouldn't cause this code.

thank you for answering my question, i will check for leaks first.

can anyone tellme where bank 1 sensor 2 is located on my 2001 nissan maxima?

thank you for taking your time to answer me.

"bank" refers to "banks of cylinders". On a v 6 engine, there are 2 banks of cylinders, on a v 8 there are also 2 banks of cylinders, on a four cylinder there is only one bank.
If your engine is a 4 cylinder then disregard the bank and focus on "sensor 2". This would be the rear most sensor.
If your engine is a V engine, then you have to locate bank 1. This bank is the one that contains cylinder number 1. Once you've found that bank, follow the exhaust pipe until you get to the second o2 sensor. That is Bank 1, sensor 2.

is there a way you can send a pic of a engine so i can see where is piston #1?
and how do i know where is sensor 2?
I see 3 sensors on my car

Post your engine size

3.0

facing the front of the engine, cylinder 1 is on the left and 2 is on the right. Sensor two would be the second sensor on that bank.

thank you very much for taking your time.....

jonathan mar

Hi! I have the same problem... My car is Kia Rio 1.3i (year of production = 2004). After scanning I got an error code P0139. Can anyone tell me where can I find O2 sensor on my car?

Thanks in advance and sorry for the trouble!

In the exhaust, behind the catalytic converter.