I would like to suggest that you move this question over to the Classic Toy Trains forum. That's where the Lionel O guage types hang out and they can probably give you much better advice.
I installed Digital Dynamics railsound in two Lionel steam loco tenders, at first they worked great but just a few minutes later, I'm getting sparks out of the trucks, still working sound, but sparks, re-checked all the wires but still sparks, is this something that will short out the circuit board? Is this something I should worry about? Should I chuck my "O" gauge layout and go to HO?