I doubt it, but its worth a try.
I set 1x 1xs to 4x (I thought this is related to the other PCI-E slots, not sure why it changed your readout from 1x to 4x.), and no change, also set PCI to v 1.0 (from 1.0a) Nothing I do changes it from 16x.
1. Is your cards BIOS modded?
2. Are you using the PCI-E slot clodest to the CPU (just had to ask)
3. If all else fails, perhaps CPU-Z is wrong. Have you benchmarked your card to see that it is performing as it should?