MIL FLASHING SUDDENLY in 06 territory turbo ghia catalytic converter damage possible?

Just recently had our 06 ford territory turbo ghia serviced (120,000km service) and 200km after the service while sitting at traffic lights the car suddenly developed a miss felt like it wanted to stall, I got it home about a 3 km drive the car lacks power with the miss sounds terrible and the car vibrates terribly with any acceleration I noticed the MIL was flashing and in the book says a fault has developed that will damage the catalytic converter my initial thought was it was similar to my old 69 model ford 302 when a spark plug lead blew off I haven't checked yet as it's pissing down rain and for a mechanical novice who has mostly dealt with older engines removing the plastic covers will probably scare me anyway.

Question is if a lead had come off or been damaged could this cause the MIL? Could it be something simple left lose from the service? We have had no issues with the car in the 3 years we have had it and this is it's first time at this local ford dealer. Also I noticed when I got home a strong strange engine odour as soon as I got out of the car when getting it home....