I need some help please

I have an 03 V6 Mondeo Ghia X, which seems to have developed a slight misfire.

Before I take it to Ford/my local garage, Id like to try and understand what the fault could be. In short I dont want to be mugged by my local Ford dealer, whilst they chase the fault. If this is simple fault, I can potentially take to my local independent.

Basically the symptoms are it seems to misfire at low revs (1k to 1.5k rpm) sometimes occasionally, sometimes several times, so that the car judders. The fault clears at around 2k rpm and it then misses again around 4,500 sort of once or twice. The judder at low revs is not due to incorrect gear selection. All through the rest of the range it seems to run fine

Apart from that, the car runs fine. Fuel consumption is about the same (+/-30ish) with no other problems

The car has 118k on it and has been regularly serviced.

Im not a techie on these so Ill wont understand the complexities of detailed answers, but has anyone any ideas what this could be

Or, is it just best to take it to Ford and get them to plug in the diagnostics?

Thanks in advance