I really hope he hasn't bought a 1.6 TDCi Focus or he'll be having DPF and turbo issues all over again. 
Sounds like a boost hose has popped now. Will spray oil under the bonnet (which hits hot parts and smokes). And overfuel like f*ck making coal out of the back. Are you sure they changed the DPF instead of gutting it?

Sounds like a boost hose has popped now. Will spray oil under the bonnet (which hits hot parts and smokes). And overfuel like f*ck making coal out of the back. Are you sure they changed the DPF instead of gutting it?