Did they offer anything useful like checking to see if the cat convertor is having troubles?
You might want to post your engine and drivetrain and mileage...
... and if this is something new or may have been that way for a long time and you just never noticed.
On a long drive, the exhaust clear at the end of the pipe can get hot enough to burn you.
Is it getting much hotter than that, to where it is discoloring something?
