This is what communities call a nuisance complaint. Local government is trying to appease the squeaky wheel. If you don't push back, the township will keep coming back. The township will wish to resolve the issue quietly. You must have an attorney and some who is good and the township knows of his reputation of breaking balls of municipalities. A letter from such attorney will usually lead to muting the issue and removing the citation. With respect to your neighbor making accusations that the exhaust caused her husbands injury, a letter from your attorney indicating that false accusations will be met with a suit of defamation. Furthermore, all records of this incident should be removed from your file. Accusations like this can follow you if you apply for a permit to carry or further allegations by your neighbor or their friends or loved one over spurious matters. In todays world, you can't just blow this stuff off. It will come back and bit you in the ass!