Been babying this 2012 G37x sedan since Day 1 with a spreadsheet detailing my maintenance work and the OEM parts I've put in. I'm at 185k KMs now and **** is hitting the fan all at once! Just in the last month, I've had to re-do the sunroof leak reroute as a perm. fix, heater hose snapped right before I was getting it replaced (bs luck), and now the P0106 / P0302 errors keeps coming back intermittently despite replacing all 6 ignition coils 4 weeks ago.... and just last week I couldn't start the engine, thought it was done for good!!!!!

P0106 Map Sensor:This thing won't go away, and it's impossible to troubleshoot really. I had it taken out and cleaned with the spray, and even had throttle bodies cleaned for extra $100 when the mech replaced the 6 ignition coils initially, but the error keeps coming back. Mech 1 told me to ignore the error. I'm seeing Mech 2 for a second opinion; he's more hands on and likes troubleshooting so he measured the voltage for the MAP sensor and said the readings were within spec. Do I just go ahead and buy a new sensor then?? I was warned that I'd have to go to an Infiniti dealer to get the ECU relearned and it might cost me potentially $$$s......

P0302 on and off, off right now....: It hasn't come back yet, but the error was present 3 weeks ago before Mech 2 took out Spark Plug 2 and found a smidge of oil inside. There was no visible or obvious leak, no traces of oil to be found anywhere else in or around the area, and simply put he could not find a reason for oil to be found in the socket. Very strange. Mech 2 mentioned maybe replacing intake gasket and plenum gaskets because they look worn out. Mech 2 then cleaned everything, put Plug 2 back in, and to this day the P0302 code has not come back on yet (only been 3 weeks). But I'm plugging the OBD2 scanner in every other day to see if it comes back because I have trust issues. Last week when it was -15C here, the engine would not start and sounded like death. Tried 10 times and lots of vibrations and sounded like engine could not fire..... for 10-15s the engine struggled and could not start, and it was not a battery issue (I charged battery after to make sure). Next day, same thing, but after 3-4 failed attempts, the 5th time worked because i stepped on gas pedal after starting engine. Somehow that worked..... and somehow every day since that day, the engine hasn't failed to start and sounds normal now.

Can any g37 enthusiasts here point me in the right direction? I need these error codes fixed soon because im getting the title owner transferred to me and in my jurisdiction it requires a valid safety test/certificate. Any CEL means automatic fail.