The Mégane II Owners' Club

Hi everyone, I am a new member and I drive a LHD megane as I live in France. I have been having problems with black smoke coming from the exhaust even though there seems to be no lack of power. I have changed the air filter (easy) and the fuel filter (hard) and have heard it could be the injectors. The oil filler cap is clean (I am told this is a sign that the head gasket has not gone ?) does anyone have any ideas ?
Cheers to all
Finners

Hi Finners,
More details about your car, its history, previous faults and the conditions under which this fault demonstrates itself would be helpful. You can also read the repair manual as pointed at in my message in Links section of this forum. Read this in particular:
https://meganedoksi.uw.hu/MEGANE_II/MR366MEGANE1.PDF