Cutting the lid off is not a big deal as it sits in a small ledge inside the housing. You can't really go too deep. I used a snap-blade knife and it cut easily.

 

So I did a lot of adjusting on it, was unable to figure out where the factory setting was, so I went to a junkyard and thankfully found one that had not been adjusted. In the end this was a good learning experience but my overly rich issue Ended up being that one of the O2 sensor bolts was broken so the O2 sensor was doing nothing and it was automatically as rich as it could be to compensate. I fixed the stud which was a huge pain but once the O2 sensor was bolted tightly it’s running good now.

 

this also occurred to me recently. i would make small adjustments to the VAF, and after an initial change in acceleration speed, eventually it would feel the same, I suspect in some cases, those that noticed an acceleration improvement might be driving with the vehicle having the CEL on. Their vehicle is probably not pulling much info from the sensors, The VAF is basically a big coil spring, so it would be a little silly to design the AFR to depend fully on the spring tension