So, I read a few threads on it in the FI section and didn't get any really good answers on what it means. I'm not running FI ... pulling this code even after an ECU reset.

Mods:
TopSpeed Headers, Test Pipes, Stillen Duel Catback, Altered Atmosphere ECU, JWT Intake, Kinetix V+ and UR Pulley

Is it a serious code or what? Anyone else pulling it and if so how'd you fix it?

Thanks!

 

P1273 Air/Fuel Ratio Sensor 1 means that one of your (pre-catalytic converter) oxygen sensors is faulty and needs to be replaced. I'm not sure which bank as it only says sensor 1.

 

Thanks for the reply.

 

Not necessarily.

First of all P1273 refers only and always to bank 1, the passenger side. Second there are a number of causes as listed in the FSM, including a bad sensor:

Air fuel ratio (A/F) sensor 1
Air fuel ratio (A/F) sensor 1 heater
Fuel pressure
Injector
Intake air leaks

Basically the sensor is reading lean for an extended period of time... Follow the diagnostic procedure in the FSM. If you don't have a FSM, get it here (if you have a G35; 350Z one should be nearly the same, but a specific manual should be on this site somewhere).