P1273 2004 Nissan Murano -

Question

My Murano had thrown this code so I changed the upstream bank one A/F sensor in the manifold. I did the recommended Nissan reset procedure and the code came back a few days later and when I rescanned the vehicle the same code P1273 came up and the eva was flashing.

Answer 1

I would disconnect the battery for at least 30min to an hour just to be sure that the self-learning reset,

you can also try to clean the mass air flow sensor with mass air flow sensor cleaner, if the problem is still there check for intake leaks and fuel pressure

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