I just changed the AF in my sienna, at right around 30,500 miles. I noticed after pulling it out, that the side that was facing the path to the engine (downstream) was dirtier than the side that I saw when I pulled the cover off (upstream).
(1) Is this normal?
(2) Does this mean that too much dirt was getting through the filter, and that I should have changed it earlier?
I recently moved to 30K af change intervals, all my manuals say so. Earlier, I would change them (or tried to) around 15K, which is what the af sellers wanted. I'm more than willing to shorten this interval if need be.
The pic on the left was downstream. The pic on the right was dirtier than looks in the picture, but still noticeably cleaner than downstream.


(1) Is this normal?
(2) Does this mean that too much dirt was getting through the filter, and that I should have changed it earlier?
I recently moved to 30K af change intervals, all my manuals say so. Earlier, I would change them (or tried to) around 15K, which is what the af sellers wanted. I'm more than willing to shorten this interval if need be.
The pic on the left was downstream. The pic on the right was dirtier than looks in the picture, but still noticeably cleaner than downstream.


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