Diagnostics are typically in the neighborhood of $100 which is pretty much an hour of labor. Depending on your region. So you're complementing them on not screwing you out of double that. See where I'm going with this? And you think the dealer is going to help you with your homemade boosted install? They'll be happy to charge you hourly, I'm sure
Well, if you didn't have a knowledgeable shop do the install after the first debacle, then I don't know what to say. Good luck, I guess.