Engine fault after cam change

[scrappydoo1982]

Good morning

 

I own a ford focus MK2.5 1.8 tdci 2008 plate. 

So now the issue, 2 weekends ago my cousin changed my cambelt including wet belt (ford can do one for inventing this BS). The car was running perfectly for 3 days then suddenly the whole dash lit up with warnings and it said engine malfunction and goes into limp mode. I turned the engine off then back on again and it disappeared for a few days but now it keeps coming on at random times.

Do you think the timing is out slightly? Would that cause an error like this.

 

It's worth noting that the EGR value needs doing soon, and that it has been on my dashboard for a while. it's something Ive been meaning to do.

TIA 

Dave