SSP engine harness

[2keaton11]

I have a couple questions for someone. I'm building project "shaded white", it has an ls3, 6 speed, nick Williams 102mm TB. The car has a Sand and Street performance engine harness with a DBW throttle body. Its seemed to cost me a small fortune to have the harness installed and now the guys have had the car about 6 weeks since I took it to them for a tune. They say they are having issues with the throttle pedal not sending a signal to the TB. I'm picking it up Friday and takin it to another tuner. My question is has anyone ever used one of these harnesses and has anyone ever had a similar issue running DBW? And should it be a concern once completed. Thanks for all input.