I have a feeling this one won't be easy...

This 2015 Mazda CX9 has a persistent Check Engine Light at 80k miles.
Dealer already performed a SKETCHY "harness repair" which involved chopping off and re-routing the harness for the Bank 2 Air Fuel Ratio Sensor... Amazing haha xD

Code set: P219B - Bank 2 Air-Fuel Ratio IMBALANCE.
What does that mean??

Let's start from scratch, collect some data, and come up with a game plan on what exactly to test on this Mystery Mazda. How would YOU diagnose this car?

THINKTOOL PROS:
https://www.amazon.com/dp/B08XXWHQVJ?...

Enjoy!
Ivan