I'm ok to wait, but not for too long.
In essence I am claiming that the Diesel Particulate Filter is blocked as a result of the Tandem Pump failing, (a warranted part). And that the blockage is consequential damages of the failure, and should be unblocked FOC.
Mike, that's not really answering the precise question. Fact, the tandem pump has failed.
As a result the fuel will be contaminated with engine oil.
The fuel and engine oil mix will then be subjected to the combustion process.
The only route for the resultant residues from this process to leave the engine would be through the DPF and then out the exhaust.
The DPF is capable of burning off soot particles, wouldn't oil stick in the DPF and block it? What about the exhaust manifold, could there be a sticky oily mess in there causing a blockage, hence no DPF warning lamp?