Hi there,   I own a 2010 1.2 petrol and just recently it's developed a problem. At low revs and gears it seems fine, but under acceleration on the motorway and under strain (up hills etc) the engine goes lumpy and feels like it's missing a beat; sort of stuttering. No engine or warning lights have shown up, so I'm slightly perplexed. Also sounds normal - just hiccups lumpy reductions in power.   Any ideas?