Hi, Any advice welcomed...
After 2 months of use after purchase 2nd hand from local garage, misfire on car - took back and 2 coils replaced, all seemed ok. Sadly misfire came back, took to Renault dealership - replaced 4 coils under Renault 'warranty' . A day or so later l noticed intermittent loss of power. Took back to dealer who said no faults on coils from diagnostic, but they updated the ecu software as they reckoned that should sort it out. Cost me £100 labour. Returning from garage yesterday car seemed lacklustre in acceleration. Today 2 short journeys I am back to intermitent cutting out, eg pulled onto roundabout, accelerated until foot to floor no power at all. Seems temporarily rectified by switching off then on again. Engine revs ok when not trying to drive! Scary and dangerous to drive so before l go back to delaer to spend more £££ only to be told nothing wrong, l hope someone else might have been as unfortunate as me and come across it.. thanks for any info.

These are prone to problems with the crank sensor but this should log as a fault code.
But then we are talking dealership.These guys go on courses to learn how to rip people off.

check cat has not broken up,cos engine misfiring when coils packed up. co meter at mot station will check emissions.

u shud go to advanced auto parts or the nearest auto zone

ask if it is genuine renault plugs fitted as ngk,s can cause misfire, try cleaning throttle body , only other problem is possible wiring loom fault but normally logs code.