Marty, Other than the standard cv's I change in regular decoders (speed steps, address, momentum) I set cv50, volume, cv54, chuff rate, cv51, background effects and cv52, foreground effects. Chuff rate was a bit tedious but you won't have to deal with it. CV's 51 and 52 are pretty simple, but the instructions read a bit like the instructions for a tax return. If so and so, add x to amount on line 10. It all makes sense tho. You are turning on or off certain sounds. For example, you don't want to hear fireman fred on an oil burner. I imagine there are similar situations with the diesel decoder, I haven't bought one yet. I intend to install a couple in dummy units, to avoid the fitting you did. If I can be of any help, you are in trouble. Only kidding, I'll help if I can, but the manual knows more than I do! Have fun, Gary