Hello fellow g35ers,
My engine service light went on couple of weeks ago. I called the dealer to ask them if they can check it for me and they told me that it would cost me $125. So my friend told me to go to autozone and get it check for free. I did and the code came up to be P1148. Like wth is that? and like how would i fix that and how much would it cost to fix that? Also do i have to get it fix as soon as possible? Because im brokeee rite now.. any help with be appreciated. Thank You.

 

DTC P1148, P1168 CLOSED LOOP CONTROL PFP:22690
On Board Diagnosis Logic ABS00A49
These self-diagnoses have the one trip detection logic.
DTC P1148 or P1168 is displayed with another DTC for air fuel ratio (A/F) sensor 1.
Perform the trouble diagnosis for the corresponding DTC.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1148
1148
(Bank 1) Closed loop control
function
The closed loop control function for bank 1
does not operate even when vehicle is driving
in the specified condition.
Harness or connectors
[The air fuel ratio (A/F) sensor 1 circuit is
open or shorted.]
Air fuel ratio (A/F) sensor 1
Air fuel ratio (A/F) sensor 1 heater
P1168
1168
(Bank 2)
The closed loop control function for bank 2
does not operate even when vehicle is driving
in the specified condition

All this out of the service manual. Sounds like the air/fuel ratio sensor. Did you have any work done in the engine compartment? Check for loose connectors

 

Nope nothing done to the engine...do i have to replace anything?

 

that typically is from an O2 sensor (pre-cat) failing.

 

hmm so should i replace it? and how much would it costs? Is it best to take it to dealer?

 

Hello, I have a 2004 G35 6MT with 122k miles, two weeks ago the service engine light went on and it's been on since. I bought a bafx reader and got the P1148 fault code.what is the right procedure, take it to the dealer or a mechanic? How bad is this?

 

Probably the A/F sensor which is sort of a pain to access, bank 1 is the passenger side, the sensor is mounted in the header not the one that's after the catalytic converter. Start by getting under the vehicle to inspect it, might be obviously broken or have melted wire or something.