For something like an exhaust or bumper mount chasing a thread with a tap is no big deal, but with something like lug nuts that could turn into a serious safety issue if not done correctly, a tap is not the tool to use.
For instance, threads are graded by class, which is the size tolerance the manufacturer is required to hold. And for safety and high stress parts like lug nuts the tolerance is very tight. If you get the wrong tap with a larger tolerance you will open up the threads creating weaker threads on the lug nut that may strip out during high stress situations. In general the taps you will find and want to actually pay for are class 1B which has the largest tolerance range, where a class 3B thread is most likely what has been called out on your lug nuts and studs, and who knows where the thread tolerance range is located in relationship to zero.
If I were you I would either get new lug nuts or a thread chaser.