Odd Problem Looking For Help

[X5 Drift]

I tried the search button and it did not work.

Fault Code 235 only

Thanks in advance. I have a 2006 x5 3.0 121K miles, that is giving me, what I believe, is a phantom fault code.
235 - Pre-Cat Bank 1, Fuel Trim
SAV runs great 19-21 MPG no issues at all, other than the SES light.
I only get 235 bank 1, there is no 236 (bank 2) or any other codes to go with it.
I have replaced the following with all new parts in this order:
All 4 o2 sensors
Mass Air Flow
Fuel filter
Fuel pump
Intake boots upper lower
CCV and related hoses (cold weather)
Valve cover gasket
Dipstick o-ring
Oil filter housing gasket
Spark Plugs
Catalytic Converter

No gaskets were leaking, just thought maybe?
The only thing that was odd when I bought this thing the exhaust was cut off at the muffler on bank 1. I took it off and welded it back with no leaks. I also checked the rest of the and there are no leaks. Also replaced all gaskets when I did the cat.

Live data for o2's look great, short and long fuel trim are good.
I did notice that it comes on while I am at and the light will go off on its own after 2 drive cycles and stay off for weeks them come back for 2 drive cycles.

The only thing I am thinking that is left, injector O-rings?
Any help would be appreciated.
Thanks