I had a cel for low voltage on the heater circuit of my upper o2 sensor. Pulled apart wheel well per the very helpful how-to on this website. I found the heat shield so rotted out that all mounting points are no longer attached. Uppon further inspection of the exhaust i found most of the rest in similar condition. The heat shield was resting on the o2 sensor.
Would this cause a short that would give me the cel?
04 wrx wagon, 202k miles, Cobb stage 1, never parked in a garage and i live in new england. Is it worth a new exhaust?

I am linking the picture from the how to thread for reference to see the heat shield: