There is nothing there to prove it's rich. All the 945 is telling you is that it's richer than 14.7:1.
It is not accurate at all. It could be 7:1 or 13:1.
The point of fuel trims are to help cars run properly in different conditions. The air changes due to weather, elevation, engine maintenance. Etc. The trims are showing you how much correction is required to keep it at a stoich mixture.
Just because the car doesn't lock onto 0 at wot, doesn't mean something is wrong. It is just estimating how far off the fueling is, since it has no idea what that actual afr is at wot. (Because narrowband o2's are not accurate or consistant when the mixture is not stoich.)
