cylinder no 3 of my C200k is misfiring on less than 3000rpm,I have interchanged spark plugs and coils but it is still misfiring.I have also put injector cleaning agent in my petrol tank which has slightly reduced the misfire,but the KOMPRESSOR acceleration is still not available.Is my MAF giving this problem?diagnostic check is also showing MAF error,any suggestions what I should do to be sure of the problem and not waste money on replacing ok parts.