So this came back to bite me about a week and a half later.
I refused to go to a mechanic and tried to resolve it myself.
I tried the following:
- Tracing the O2 sensor wires to the ECU plug
- Swapping the sensor
- Flashing 3 other tunes
None of this worked so I decided to revert to the stock header. I went to get gaskets before going under.
Here are the part numbers FYI:
Overpipe gasket 44011AG000
Manifold Gasket 44011AC030
Visually Inspecting I saw that there is some carbon build up where the gasket maker used to be.
I figured trying a simple gasket swap would work. Inspecting the gasket, it's clear the shop reused the overpipe gasket (which imo is a big nono).
It's clear that the gasket was reused and caused a small exhaust leak. This apparently is a known cause such codes to trip. Despite not having an audible indicator of an exhaust leak, the picture should be enough evidence.
It's been 2 weeks since the gasket replacement and no CELs. If I get them, I'll update this post with a solution.
That's all for now!