Would bad spark plugs cause these symptoms?

I really doubt it is bad spark plugs. Usually when there is a bad spark plug you will get an engine misfire which will set a code. You would also notice other problems, like your engine shaking and your check engine light on. It is possible that your spark plugs caused this but not likely. It is probably more like a fuel system problem...like maybe your car isn't getting enough fuel because of a clogged fuel filter or bad fuel pump. There are a lot of other things that could be the cause too.