Change to high quality filter lead to drastic drop in fuel efficiency

[1stToyota]

Originally Posted by N9QGS

I tried a K&M oiled filter, and after about a month or use was disappointed myself with the lack of MPG I was obtaining, so I switched back to the Toyota Air filter and everything was fine again. Im not sure how much learning or tolerance are in these ECM, but I personally wont try an oiled system again cause I heard that also can fowl other things down the road, don't know if myth or not. I wish you luck with your decision and outcome.

They say it's a myth, but logic says different...with a little over-oiling the oil has to go somewhere, MAF meter (yes, w/ heated wires ) is downstream within just a few inches from the filter.