P1273 Nissan -

Question

I changed the forward O2 sensor on bank 1. after 70 miles or so, SES light came back on, same code...

Thoughts?

Answer 1

first you can check the body grounds.

 

 

 

check fuel pressure At idling: 350 kPa (3.57 kg/cm2 , 51 psi)

 

check to see if you have any intake leaks.

if everything checks out could be a problem with the harness, and the harness has to be checked

 

possible causes:

 

- Faulty Air fuel ratio (A/F) sensor 1 Bank 1 
- Faulty Air fuel ratio (A/F) sensor 1 heater Bank 1 
- Fuel pressure
- Faulty Fuel injector 
- Intake air leaks
- Faulty Air Flow Meter