CarAdvice provide a very good summary of the issue for some Toyota drivers in Australia right now:
Toyota Australia is facing a class action lawsuit over issues with the Diesel Particulate Filters (DPF) in 2015-18 HiLux, Prado and Fortuner vehicles powered by the 2.8-litre turbo-diesel engine.
According to the legal firm considering the claim, its clients have experienced "increased fuel consumption and a loss of power of the vehicle" because "hard deposits accumulating on the DPF oxidisation catalyst" stop it reaching the necessary temperature.
The claim says the DPF may be defective because the HiLux, Fortuner and Prado don't burn particulate matter in normal urban conditions, where many owners spend time, creating particulate matter buildup, DPF blockage, foul-smelling emissions from the exhaust, increased fuel use, and greater wear and tear on the engine.

It acknowledges Toyota contacted owners offering to clean or replace the DPF in affected vehicles, and retro-fit a manual regeneration switch, but says some owners have been dealing with the issues for a number of years, causing "unnecessary inconvenience and expense".