Recently, while observing Lambda (w/ AST Retreiver), I noticed that it was steadily climbing. With the last measurement it was around 70 - 75%.
So I did some investigation and fixed the problem. Of course, after doing so, I did some reading and found a number of interesting articles and so the better ones are included in my discussion.
If interested, it's
MENU#4a on my web pages. It is part of the ON-OFF ratio tests.
Of particular interest, check out the "COMMENTS" section and the "real-world" test of various filters under "real-world" conditions in a "real-world" auto. It is MANDATORY readiing IMHO.
The 'good' news is that I was able to 'save' an MAF and IAT with this 'fix'. Good info for those with "hot-wire" MAFs.