I need help

So I have a 2010 bmw 328i I keep getting a p0131 low voltage bank 1 sensor 1.

I started looking around and found my o2 sensor had completely melted I replaced both upstream 02 sensors. I verified my 02 sensor heater fuse wasent blown took the whole intake manifold off and verified wiring and harness wasn’t damaged verified continuity with multi meter checked all my fuses I feel like there is a short somewhere but I can’t find it !