Thanks for the explanation. That is helpful.

The reason I ask is dialing in AFR is still a bit tricky. Seems that the most responsive change was to update the MAF calibration. Now it seems difficult to use B3647, A0008 and B3618 to wok together.

I guess the question I am trying to ask is: Is there a better or easier way?

I finally understand most of the basics but wonder if I will ever get "done".

Anyway, enough crying.

Thank you for all of your help. I really appreciate it.

Bob