so awesome news today...my CEL went out!
I'm thinking one of two things happened:
1. maybe the DME adapted to the VRSF dp and the catted version actually works well enough, or
2. the O2 extender/anti-fouler I made for the rear O2 worked. I installed it this Tuesday. No change to the CEL on my 60 mile round trip drive to work Wednesday. Didn't drive on Thursday. Today...2 miles into leaving I noticed the light was out and was still out upon returning home this afternoon. Either way, I'm not complaining.