Back firing

Recently purchased 2012 Nissan Murano 6 cylinder. FWD. Upon acceleration, I hear what sounds like the car is backfiring. Does not happen all the time but seems prevalent upon quick start. The accelerator pedal is very sensitive, and I need to consiously think about light preasure on the pedal. Of course, taking it to the dealership didn’t work, because I could not recreate the problem. It’s still happening. Any Ideas on the problem? Thanks Jacques

Did the dealership check the ECU for stored codes?
Did they check anything else?
Is the vehicle under warranty? If not, bring it to a reputable independently owned and operated shop and relate the tale. There are a lot of possibilities and most of them will post codes.

It could be as simple as a faulty injector (pintle not seating) allowing raw fuel into a hot cat converter, or as simple as a bad sensor sending a fault signal to the ECU and messing with the fuel metering. Whatever it turns out to be, metering or timing related, chances are it won’t require surgery on the engine itself, so don’t be afraid to find out. Allowing it to continue could kill the cat converter. Hopefully that’s still okay.