What am I missing here? I have searched but have not found a good explanation of the basics of IQ and how it all works. Why is a higher mg/str number a lean condition? does mg stand for milligrams? Does str mean stroke? Intuitively more mg of fuel per unit of pump stroke should mean more fuel being pushed to the injectors. The car smokes (white) massively at idle so that seems unintuitive because where is all the fuel coming from to make the smoke if it's lean? Is 27.4 mg/str too high? I understand that a higher number means lower fueling (too lean). On my 2000 Jetta ALH automatic I am seeing this IQ at idle:
