2000 Pathfinder 120,000 miles. Code - P0153

P0153 - O2 Sensor Circuit Slow Response Bank 2 Sensor 1

I have replaced the o2 sensor and the light keeps coming back on after clearing the code. Everything runs perfect with no other issues. Other possible causes after doing a little reading are:

- Faulty Front Heated Oxygen Sensor Bank 2 (Replaced)
- Front Heated Oxygen Sensor Bank 2 harness is open or shorted (Checked - OK)
- Front Heated Oxygen Sensor Bank 2 circuit poor electrical connection (Checked - OK)
- Inappropriate fuel pressure
- Faulty fuel injectors
- Intake air leaks
- Exhaust gas leaks

I ran some injector cleaner through a new tank of fuel, cleaned the MAF and the code remains. With this possibly being a low/slow voltage issue, I know it's time to replace the battery. Could a weak battery be causing this code by chance? Any suggestions??

I read something about there being a possible grounding issue from the engine. Not sure if it was for these year models or not so it may not apply to me........

There was a TSB for poor grounding of the EGI harness causing O2 sensor codes on 99-00 Pathfinders, but it was P0153 wasn't one of the codes listed on the bulletin. It was Nissan TSB# NTB01-048a. It involved checking the voltage drop at the EGI grounds on the intake plenum and installing an overpriced harness kit between the grounds and the right bank cylinder head. The harnesses can be made using some 10 gauge wire and eyelets and it's probably worth doing if it hasn't been done already. As far as a weak battery causing the code, it's possible, but I would suspect you would see other codes, as well. Charging system issues can do funny things, so you should make sure your battery and charging system are in order. The code you got is for slow response. I'm wondering if you got a bad new sensor or possible replaced the wrong sensor? Bank 2 Sensor 1 would be the front sensor on the left bank, or driver's side of the engine. It would be helpful to be able to view the front sensors operation on a scantool.