I have had this exact issue for a couple months now. The fluctuating idling at startup that. If it happens to stall during these fluctuations, I get a CEL. ONLY if it stalls though. Did the whole new Air Filter, cleaned MAF, cleaned EGR, and it was good for about 2 weeks, but it came back. The scary part is, if the VX isn't running at a normal temp/warmup, it will do it. and when you are stepping on the brake and it suddenly wants to rev, you gotta be ready to step on that brake just a bit harder. Once she is warmed up, she cuts that out though.

I have been trying to troubleshoot whether I was running lean or rich. Both can cause fluctuations, but both also have different exhaust signatures. I don't have dark emissions so I am leaning towards running lean. My next step is to replace the FPR and clean the S/C fuel rails, in case of some residue/blockage. Probably replace the EGR while I am at it. I have been saying this for a few weeks now, but with tight pockets and winter starting to shadow me, I think I am allowed to continue to procrastinate.