[officeplant]

>Most often the worst case is fouled spark plugs, which are wear items meant to be replaced at regular intervals.

You do realize we are talking about diesel's here, they don't use spark plugs. They use Glow plugs because diesel engines don't rely on spark to cause combustion, its just heat and pressure.

Nor do they rely on downstream oxygen sensors like a gasoline powered car. They just use tuning software to up the turbo boost pressures and adjust the fuel mapping. Some guys literally just have a button to hit to briefly swap to an alternative fuel map that maxes out those fuel injectors briefly.

The main problem with rolling coal is damage caused by the extra exhaust temperatures from dumping extra fuel into the combustion process. Plus the fouling up of entire exhaust system over time. Sometimes causing fires within the exhaust system (see Ford's 6.0L Power Stroke meltdowns on youtube)