A few days ago, I bought a Borla axle-back exhaust for my 2006 v6 Mustang, and it was supposed to be delivered today. When I got home, I saw a package on my doorstep, so I set it by my car, then took off the muffler. After opening the package, I realized it was just a seat for my motorcycle. I really don't want to put the muffler back on just to remove it again tomorrow. Would it be detrimental to leave the muffler off for one day? I wouldn't be traveling far, just to my school and back. I won't travel above 20MPH. I'm afraid the exhaust might heat up the undercarriage of my car or something similar. I tried looking around, every thread about a muffler being off just talked about a muffler delete and straight-piped exhaust.

 

I have ran mine for a short distance in an emergency. Watch for exhaust fumes to enter the cabin area. Be weather alert, if it is extremely cold out a red hot valve could warp with frigid air cooling off the heads at a rapid rate. That has been my only experience & old exhaust systems before catalytic converters.

 

Can you get at least one hanger back on? If so, I wouldn't worry about it at all, except for the fumes that Bud already warned you about.