For those fighting this as well:

Well been fighting this one for a bit now diagnostic software indicates a short on the secondary o2 sensor. My Plx devices odb2 monitor doohick shown -6% on the Long term fuel and after cleaning the map sensors and finding a leak at a intercooler boot (repaired) it has gone to -7%.

Also my coolant used to sit pretty at 194 but is now creeping as high as 205 on the highway.

The shop I go to tried to reset adaptations but it wouldnt let them they are thinking i need a new DME. Anyone else run into this?

I now have both o2 sensors brand new and even swapped to ensure they werent a bad set brand new.

also on fuel trims the long term when I read -7% is that telling me it is removing 7% of the normal fuel consumption? I think im running a little lean from this hence the coolant temp change but if i fixed the leak and it even drives better now shouldnt it be moving away from the extreme? I guess im looking for a better understanding of what I should consider ballpark of what it should read.

note I also have jcw injectors but they are tuned by RMW and been this way for well over 100k

 

If you can find a fix to this then I applaud you. I gave up after the fifth fix was thrown at it.

-reset adaptions
-update software
-replace green gasket at SC (vac leak)
-Replace bypass valve (vac leak INTO the valve, not through the valve)
-Replace IC boots (didnt even bother, another vac leak)