Civic exhaust or motor sounds bad?

Ok so I was driving down the highway and I started to run out of gas… There was no gas for a long time so I came really close to empty I got to the red line and then found a gas station a bp… I pulled over and as I was coming down the ramp my sound started sounding weak and let me say I have a full exhaust system that sounds nice and strong… I knew it was sounding weak cuz of the gas being so low but after I filled up I thought my car would sound back to normal but it hasn't?! My exhaust sounds like a lawn mower lol and no for those who think all hondas sound like lawn mowers, mine never sounded like that before… It just sounds weak in power somone help please what could of happened and what can Ido to rule out some problems?

Chances are that it backfired inside the exhaust system when you ran out of gas. The system is now damaged.