Blackbird

As you may or may not know I have been chasing a very frustrating fueling issue where when I decel or switch gears my A/F drops down into the 11's and 12's until I touch the thottle again and then it shoots way up to 16-17:1 for a second and then settles back in. Also if just crusing and then stab the throttle the car goes very lean for a split second. Side effects being KR and a very annoying surge.

So today I ran the car open loop and found the symptoms to be the same.

So at this point is it safe to assume it is not something like a vacum leak or exhaust leak mucking with the 02's ???

I know the program is ok as if I program another 98 with similar mods with my program that car runs fine.

When I run open loop it's all about the MAF and MAP to make fueling decisions right? I am wondering if I could have a MAF that is partially wigged out?

I noticed in the logs this morning that there are periods of time that the 02's read basically zero. I found this strange as when running open loop the 02's are not bouncy bouncy they just read whats going on.

Anything you all can think of I should log or test to try to track down my problem???

TIA!