Is there such a creature does anyone know?
I am hearing people having problems with sewage backing up in neighbors basements and their own and was told to get a "die test" done.
Does anyone know what this is?

Very common here in PA.
The inspector will put dye down your commode, wait, and see where the dye comes out. It detects leaking pipes, leech beds, improper routing, etc.
Not terribly expensive.
Good luck

Dye tests are a complete sham and only find a problem with a currently malfunctioning system that is grossly defective.

Dye test info: http://psma.net/dye_tests.html

There are very specific standards of practice as far as septics are concerned. Make sure you get what you are paying for.

Here is an example of what a dye test really is:

Say you were buying a car and you noticed that oil and anti-freeze were leaking out the tail pipe and smoking. You would assume that the engine was shot right? That is what a dye test does, it shows you when a system is completely shot and no longer functioning to the point is is spilling sewage to the ground.

A good septic insepection will test to see if the system is functioning as intended.

Take that same car and lets say there wasn't any oil or anti-freeze coming out of the tailpipe. But you had mechanic check it out for you and reported that it was only running on 2 of 4 cylinders, there was oil in the anti-freeze and the transmission was slipping.

You certainly would not buy that car if you knew that right?

A dye test is like seeing oil dripping from your tailpipe but it does not tell you if the engine is any good. See my point?