I've discovered the previous owners didn't replace the heat shield when they swapped out the headers. At least they wrapped the exhaust. I've bought a headers since I was throwing a rear O2 code and wanted to add a catalytic converter. New headers aren't wrapped. How critical is the missing heat shield? Should I buy a replacement or should it be fine without? Weather is cooling off but I'd like to do some track time next year.

 

The heat shield should be replaced as the added heat to the engine bay, is not a good thing. Even if it is wrapped, the heat shield should be in place.