My SES light keeps coming on and the codes are 0138 and 0139 and that is the Bank 1 Sensor 2. Where is that O2 sensor located on the vehicle and are they hard to change? Is this a common problem on these vehicles?
From whatI've read at Edmunds.com, and my own experience, the answer is YES. O2 sensors seem to be a problem. I bought my 2001 Pathy LE 4WD used with 30k on the clock in 2002. In one week the Check Engine light came on. dealer says they replaced 1 or 2 of the O2 sensors. Happened again & again at different mileage intervals. Found a Straight Shooting mechanic in Long Island near my place of business. He cleaned them - put in 2 bottles of STP Fuel system cleaner, and was good for 30-40k miles. At 112k Miles, happened again. I put in 2 bottles of STP, and it's OK again. Costs to replace all of the O2 sensors - I think there are 4 - $800!!!!
One time I used 2 Bottles with a full fillup - 16 to 18 gallons of gas. Another time, used one bottle at a time. When the LI mechanic did this for me, he did reset the codes. On another occassion, the CE light went out on its own. BE SURE TO TIGHTEN THAT GAS CAP AFTER THE FILLUPS. That and the greater amount of ethanol being used seems to be the culprit fouling the 02 sensors.
I think the O2 sesors were under $150 each from courtesy nissan.. dont remember exact price.. reprogram by dealer was $170.. I replaced the sensors myself.. easy to install, but routing the wires was difficult..