Welcome! I would start with the code itself and report back. Also, perhaps the tuner wasn't exactly correct since I'm reading the delete and the code happen at the same time?
Welcome to the forum... I will say, if you should care for any vehicle, the EcoDiesel is one of them :D
We've got plenty of reading here to keep you busy.. we're glad to have you onboard, enjoy!
I would love to help, but most tuners have specific instructions how on to proceed. The general standard is to tune first, then remove the components. Have you reached out to SFT for instructions? I know we have some Sofa King customers here, maybe they can help...
Most aftermarket warranty companies will say anything to get out of a claim. They might be right, but I would fight it like no other. That's why I hate them.
It's honestly a crap shoot! But, if you can financially recover for a bad failure and you feel like it's a nice buy, then do it. They are nice smooth rides.