I would be curious which error would be reported in such a constellation by your ECU. I would expext error codes P0170 or P0173 (fuel adaptive map maxed out), as there is only a certain corridor foreseeen to adapt the fuel amount based on the standard mappings.
Ding ding ding ding! Winner!
P0170 or P0173 it is. Not entirely sure what it means. Maybe it is the back pressure issue?
