Possible flaw in design of air filter housing on 150 series 2.8l Prados, may damage engine.

[gxl_d4d Advanced Member Find all posts View Profile Close gxl_d4d]

I'll let you know re the shim in a few months. I've only had it in for 4 months. Even before it, I only ever had a light talc like film which was barely noticable when running a finger over it. I got an aftermarket filter with the shim kit. I'll give it a go.

[Daniel150 Member Find all posts View Profile Close Daniel150]

I had a similar result to you. Never anything more than a light smear.
Now before what I say next gets taken out of context, I’m a firm believer in good filtration and clean air, oil and fuel makes for a happy motor.
However….
Toyota claim the dust is less than 5 micron that gets through the air filter. Factory fuel filters are approx ten micron, even a fine secondary fuel filter is only 5 micron.
With the above in mind, I’m ok (not happy) with the fine amount of dust that has made its way through the filter. I would assume it’s no worse than what gets passed through the fuel system on a daily basis anyway.
I have found the dust is better controlled with a ryco filter so that’s the best solution I have at this stage. Any feed back would be great thanks d4d!!