i had the exact same problem with my k11, it turned out to be the throttle body, which are common for going on micras
evern with having a new one fitted the same problems are starting to happen again with mine 6 months down the line.
dont leave it too long to change the t/b as you will get the same scenario as me, where the t/b stops working and just jolts you forward and back under any pressure on the accelerator.