DPF filter

[mackan]

Usually dpf is ceramic and you can not see "trough" it like a catalytic converter so, if you have damaged it , dpf will usually be blocked or the ceramic broken and it will not take care of the soot and you will have black smoke in the exhaust, the reason why i asked about MAF and injectors is that you can have a mechanicly damaged injector that wont trow a faultcode, in worse case it can burn trough piston, it will "smoke" but you wont see it because the dpf will take care of it (clogg up rapidly), sencondly MAF can be quite tricky to T/S, if you are "within limit"of MAF signal it wont trow any code ie:if it reads 10% to much A/F it will signal ECU to meet that demand and it will "smoke" more.

best of luck!