Had this in a few weeks ago,not firing on 1 cyl.Swapped coils round to see if it was a coil or something else.Replaced 1 pencil coil,then drove for 10 miles no prob.Thought i'd do an emissions test to check for cat damage and whilst running on the ramp another cyl went down again (different one).Replaced another coil and thought how lucky this happened before i gave the car back,explained it to the customer anyway.

Two weeks later customer rings up to say same thing again.I check and now yet another coil packed up! This time i replace the 2 remaining coils so now all 4 coils are new (geniune Bosch).Customer happy again.

He's just called again to say same thing happened again!

Any suggestions please before i look again next week? Any codes logged so far just say 'misfire on (relevant) cylinder'

Thanks
Colin.