Mazda reckon the fault was with the injectors (one injector in particular); that they were injecting too much fuel & causing the dpf to clog. The Customer Care guy I spoke to the other week stated that the DPF on my model was more suited to regens in city driving conditions anyway. So, if it's the injectors that are the problem, what's causing them to inject too much fuel? The
ECU? Another sensor? Because if that's the case, why wasn't this picked up at previous services? and if the problem is indeed with anything upstream of the injectors, why is it the only sensors they're replacing are 3 temperature sensors? They're not part of the injector or fuel delivery system?
I'm not expecting you to give me an answer, by the way; it's just infuriating that there's an apparent fault with the injectors (at least, that's what Mazda are blaming it on), and there's absolutely no enging warning or alarm given until the DPF packs it in & the repair bill skyrockets.
Incidentally, is testing of injectors something that should be done during routine or scheduled servicing?