2012 M56 with 79K on the clock.

Coldstart and everything seems fine but within 4 seconds I feel a vibration. Received codes P0202 and P0203 (Injector Circuit Fault on Cylinder 2 and 3). Let the car warmup (roughly 10mins) and as it idled like s*** I also received P0333 (Kock sensor bank 2 circuit high input). Clear codes and turn the car off for 10 seconds - try again and no issues. Drive around the block and park the car for another shut down and start up - no issue. Take the car to work and when leaving 8 hours later I have the same issue.

Last night I took a look under the hood and noticed the driver side intake partially disconnected from the Mass Airflow housing so I remidied that. Also went ahead and cleaned the grounds on the driverside of the engine block and strut tower. This morning I run into the same issue - have to let it warm up and then after restart everything is back to normal.

I'm thinking that since it's two injectors showing issue they aren't actually the problem and it's probably something to do with wiring but I wanted to get the communities input.

Thanks in advance for any feeback.

How is the situation with your air filters?

I'd attempt to do a reprogram first to see if anything changes, but I also feel like for only #2&3 injectors to act up, I'd start with external possibilities.
Check oil level as well - a lot of issues start from there.
Assuming you're not the original owner of the car, I'd check with Infiniti as to what kind of work has been done this far, including the HPFP issues.

Thanks for the reply.

I removed the top air filter ductwork and both filters looked fine. Oil was replaced 3K miles ago but still showed full. I am not the original owner - purchased when at 68K miles on July 2018 and verified with infiniti that there were no outstanding recalls in effect.

Problem happened again this morning - let the cars temp get to 114 F and then shutdown for 10 seconds. On restart no issue. I'll try a reprogram after work and report back.

Thanks again1

After work I reprogramed the ecu and the car fired right up! (Note car was baking in the high 60 deg weather)

This morning I tried to start and again after 4-5 seconds of running just fine the car starts vibrating again. Let the car coolant temperature get to around 94 and shut down restarted with no issue. Just to note the temperature was 41 outside.

If anyone else ends up having this issue I found the following Technical Service Bulletin.

SB 2011-2012 M56; Engine Runs Rough with MIL "ON", and Has Paired Inje
Summary of ITB11063:
IF YOU CONFIRM:
The MIL is on and has one or more of the following paired injector DTC's:
"P0201 and P0206", or "P0202 and P0203", or "P0204 and P0207", or "P0205 and P0208".
That the vehicle has a lack of power and accelerates slowly.
Engineis rough, or sputters.
Will not go over 30-40mph.
ACTIONS:
Replace Engine Room Harness with parts listed on page 2.
Replace ECM and register vehicle VIN.
Do not replace injectors

Seems that part of my harness on the backside of the engine wasn't properly secured and "hanging loose." Resecured the harness and I haven't had an issue since.

Glad you figured it out. And thank you for reporting back!

Thank you for reporting back.
I bet Infiniti would have LOVED for you to buy the entire harness, after diagnosing the issue for you.