Interesting read about open filters and MAF's

[Poodle]

Pearoast. Tbh without running them in an actual vehicle for an appropriate number of miles the test is meaningless. That study has been conducted in a lab, as such it's almost entirely irrelevant to the real world. The fact remains it's a very common problem and there are regular posts of people who have replaced the maf with a new genuine item, blaming the old maf as k&n have, and then had that fail quickly too.