Sold a car. Buyer found out there are engine issues (unknown to me)...I want to return her money and get the car back.

I released interest on the title and did the online DMV form stating I sold the car. How to do I fix this?
Does she reassign to me with the original title and I go to DMV and pay the man?

Thanks for any help,

Got some input over in Car/Bike (mostly that I'm an idiot for taking  back "as-is" car...), but I thought I would report back on how DMV went.

Went in and waited 2 hours. DMV told me, you're fine. You have car and title and the signature/release date and mileage are fine. They don't care about milage declaration on cars over 10 years old. They also stated, the bill of sale for the new buyer will have the actual sale date and the back of title date would not cause a +30 day late fee for title transfer.

Sold the car Friday and have moved on.