He was pulled over last week. The officer said he had an illegal muffler modification on his car. However, due to other circumstances that took place during the traffic stop, my son was not cited for his muffler. Rather than have him be at risk for receiving a "fix it" ticket some time in the future for his muffler, I would like to find out now if it legal or not. If it's illegal, he would rather "fix it" on his own and avoid the ticket and fine. Thanks.