Yeah it could be running rich. You could also try resetting the ECU, see if that changes anything (disconnect battery, press brake to drain remaining electricity in system, reconnect battery).
It's nothing too serious if it's only the occasional pop. When you start getting major hesitation and backfiring around the 4000-5000rpm mark you need to start replacing stuff, usually the fault comes down to spark plugs need replacing or re-gapping, coil packs, o2 sensor, fuel filter, fuel pump.. the list goes on - common problem with lots of common causes. Your occasional pop could be early warning signs of the above. Only time will tell.