[mwebb]

Originally Posted by t vago

However, that is something that we would do. I imagine that most people who buy these EFIE things do not actually take the effort to ensure an accurate AFR by buying a $300 or so wideband O2 sensor to monitor their output. What do they do, instead?

"most" of those sell their mistakes on craigslist
with a statement like
"i do not have time to complete my project"
which really means
" i screwed everything up and i have no clue how to make it work right again"

google a plot of a graph for 5 gas emissions , look where NOX peaks
at about 16 or 17 to 1
Knowing that NOX forms at very high combustion temperature s , you should not operate at "slightly lean" ....
at conditions leaner than "slightly lean " combustion temperatures DECREASE.
as marked by the NOX graph in the 5 gas graph

most people should not tamper with this