EDIT: I just realized this thread is years old and was suddenly revived today by ecoinsane. Would still enjoy discussing.
Quote:
Originally Posted by Christ
MAP compensates for manifold pressure by adding fuel. It doesn't care about flow.
MAP systems assume a basic map of manifold pressure versus known VE under OE circumstances, and add fuel based on that. It will run pig-rich because he's stuffing hot air in the engine under high RPM situations, to the extent that the O2 can't recalibrate the mixture enough to compensate. If he does it long enough, the cat's toast. Raw fuel in a catalytic converter is a good way to have a car fire, by the way. I've had it happen.
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Hi Christ. Have not exchanged ideas with you in a long time and these comments are interesting. I have been running a WAI on my 1998 Civic for about two years. I passed CA emissions last August after about 15 months running the WAI at a rate of 12,000 miles per year. The tech said that there was a little unburnt fuel in the cat, but nothing to worry about. I actually see richer AFRs on my Ultra Gauge when the IAT is colder, leaner when the AFR is hotter. I just had that experience yesterday and today, on my commute, climbing a steady hill at 1800rpms for about 1.5 miles, 40 mph or so, 75-80% load. I have had nothing even suggesting fire. So I wonder if you're overstating the danger a little. What do you think? Maybe my driving conditions and set up are different than you are talking about, different in ways that matter?
And I did this test, which I'm sure is not perfect, but I wonder if you'd even think it is good and why not:
http://ecomodder.com/forum/showthrea...tml#post233571
As you see, I thought I saw a modest but measurable improvement with the WAI of about 2%. A source of error I have become aware of might be that--not having cruise control--I held a steady throttle position of 16.1% using the Ultra Gauge.
I'm open to correction and debate. Interested in learning.
-james