The Carfax reports I have seen do not include past owner's name / contact info. They contain:
- Accident / damage report
- Number of Owners
- Service records
- Open recalls
- Last Odometer mileage reported
- Date of Manufacter, titling, registration, and inspection info.
How or why would anyone give you a free Carfax report? Why not pay for one yourself?
The dealer who received the car from the factory and any dealers that serviced the vehicle are included in the Carfax listings. You may be able to go to those dealers with your VIN to find the original owner, if they will disclose that to you. If they won't then ask the dealer if they could contact the past owner and give that person your contact info. The past owner can then decide if they want to talk to you or not.
The title when you purchased the vehicle should of had the previous owner's name on it. The DMV should also know, but I'd don't know if they will disclose that to you.
I'm surprised the dealer can not return your vehicle to the stock stradegy. The IDS / WDS has this capability. They would have to flash a new computer (PCM) from scratch if you purchased one anyways. Perhaps there is really a problem with your PCM, independent of any changes the previous owner made? Can they communicate with the PCM at all?
There is a special proceedure they need to use when flashing a new PCM when the old PCM is completely dead. It does not rely on any of the old PCM's data (since the old one is dead!). I suggest you ask them to use that proceedure or try another dealer that has a clue.
P.S. Why are you typing in all CAPS? I hear you load and clear!