I recenlty purchased a cat back from flowmaster and the pipe that attaches to the over the axle pipe wasn't expanded on the converter end. Just thought i'd share that. And there was a three week back order on the part. I didn't want to get it expanded and find out it wasn't the right length, but I did anyway, and it worked. Needless to say it sounds good, but I might think twice before I buy from them again.
On the other hand the guys at summit were willing to ship me another after they picked mine up which was more than expected.

 

I had similar problems...
Ordered a Flowmaster catback from Summit....

one pipe wasn't expanded... and instead of the Super 40 muffler I was told by both companies the kit would come with, I got a 30 series...

I decided to keep the 30 series (which overall is bigger than a super 40) and they sent me a replacement pipe @ no charge...

Summit would of also taken back the entire kit had I asked...

Things happen & I've been treated good by both, so I will continue to buy from them...

Unlike TPIS, which lie and yell at their customers... or Ex customer now...

Raf