Several years ago they installed a Flowmaster Deltaflow 50 muffler on my TJ. After a while it started rattling at a specific rpm when it was warmed up. April 2014 I took it back and had them replace it with another Flowmaster Deltaflow 50. A couple months ago it started rattling again just like the first one. I finally got around to taking it in again this morning. I got there a little before opening time and by the time they got it up on the rack it had cooled off enough that it wouldn't rattle. I tried to convince them there was a problem but they said they've never heard of a Flowmaster acting like that and for me to have two in a row would be as rare as winning the lottery. We took it down off the rack and I drove it around for another 20 minutes to warm it back up. It was stubborn but finally started rattling and they were astonished. The second Flowmaster was still under warranty but they suggested we replace it with another brand since two had already failed on my TJ. Mark the store manager submitted the warranty claim and installed a Magnaflow muffler to replace the Flowmaster at no cost to me.
Thanks go out to Mark at Marco Muffler. If you need muffler work, Marco Muffler is great to do business with.
