I put in 200 cell high flow cats on my wife's car(Audi A4)and use to get an occasional CEL on her car when under heavy load (a/c on in 90+ degree weather and under moderate acceleration). That was until I installed a 90 degree o2 CEL spacer similar to this.
https://www.aliexpress.com/store/gr..._509896257.html?spm=2114.12010612.0.0.LaBf4y#!
I had to play with the positioning of the spacer a couple of times before it was able stop the CEL from coming on. I had to turn it to go against/opposite the exhaust flow and had to play around with the height but no CEL's for a couple years now.
Not sure if it work on the Raptor but maybe something to consider to prevent the CEL. The one on the link I attached is just for reference only that I did a quick web search for.
---------- Post added at 01:20 AM ---------- Previous post was at 01:12 AM ----------
Forgot to add that there no tune installed on her car to disable/ready mode the o2 sensor yet. I waiting for the warranty on the car to expire before the tune goes in, my dealer turns a blind eye to the exhaust.
