My peugeot 206 (year 2000, petrol model) has developed a misfire. i was
driving along fine one minute then it started to misfire.

symptons: lack of power, poor idling and misfiring (sounds like fuel is
igniting in the exhaust pipe but not loudly back firing out of the exhaust
pipe)

I have re-newed the plugs, checked the valve clearances, compression
tested the cylinders, checked that all the plugs are sparking.

Is there anything else i can check to rectify this problem before
reluctantly taking it to a garage?

Thx in advance
Redhotmax