It's a 08 GTI with a 3'' jetex TBE ,K+N intake and a rtech remap ,replaced plugs 4000 miles ago(oem plugs) and diverter and PCV were replaced 1000 miles ago,getting a spluttering/miss at idle and up to 1500 rpm but ONLY when the engine is hot it started to happen today ,no ecu/fault lights . any ideas guy's ??