2011 G37x bought used, car ran fine 80% of the time, had a CEL, SES, engine light code of P0106 and occasional hard start, stalling upon start, rough idle sometimes, about a half second delay starting from stop that was annoying, not having a reliable jump when needed to leap out in traffic was unnerving. Light would go off occasionally but return. I cleared the code a couple of times. At a dealer visit for the first oil change on my watch I explained the situation and requested they change the MAP sensor. When I picked up the car they said they didn't find anything wrong (I had cleared the code) and they didn't replace the sensor. So I bought a replacement sensor and did it myself, still had the problem. Next time at the dealer, I didn't clear the code, they updated the ECM (under the power train warranty) and the car has been great ever since. If they don't have a code to report to Infiniti they won't do the work under warranty.