I HAVE A 2010 INFINITI G37x and it has engine light just came on so I checked it with my code reader and this is what it says.

these can assist https://www.troublecodes.net/p1codes/p1121/
https://www.youtube.com/watch?v=ZKxwCsDeY9E

The engine harnesses need to be thoroughly inspected, mice love to chew them to pieces for nest material and to sharpen there little teeth...

Code is transmission related, might of caused a problem internally and that is why your code is present and you are having problems shifting.
Is there any physical damage to the transmission pan ? Dent could of damaged a component inside.

code p1148 refers to closed loop control-bank 1-inoperative===causes--wiring--HO2S front--ECM

Check the wiring is in good condition, replace the HO2S sensor.

Hello,

In the code reader book are codes and possible problems, O2, EGR, etc.
Autozone, Orielly's should be able to help, they can code the vehicle also and help you find and fix the problem. Call and ask.

I hope this helps.

this one is car machanic

for your infiniti FX35,
P1446 - Infiniti Type Powertrain - Manufacturer Controlled DTC - Manufacturer Controlled Description Evaporative emission (EVAP) canister purge control valve - malfunction
Cause Wiring, EVAP valve, mechanical fault, ECM

or you can ask the 24 hrs live technical support http://www.spobd2.com/service/, they will like to help you, good luck

CHECK THE MASS AIR FLOW SENSOR

You need to have access to a code reader to turn the light off.  The best/cheapest way is to go to a local auto parts store and most of them will read the code for you for free and then turn the light off.  I would strongly suggest taking the code to see what might be wrong though.  Good luck.

Have you cleared the codes at least once?
The new o2 sensors should have removed all those codes.The sensor closest to the engine b1s1 may be defective.Check wiring and plug to that one closely.