2013 to miss fire head has been replaced

[Drthomps01]

I am looking at purchasing a 2013 Transit Connect. I went to go look at it today when I started it up the check engine light was on I was not able to read any codes or check anything mechanically out with it because I did not have tools with me and I am 4 hours away from home. Anyway it's got 61,000 miles on it the head has either been replaced or had work done to it because it is clean I can see where the motor mount bolts have been broke loose so I know it's got a new or replaced head or reworked head on it nevertheless I have one dead cylinder the one all the way to the right toward the driver's side that cylinder is dead from unplugging the coil does not change any thing in the motor still has a rough idle I swapped the coils made no change.
The guy that is selling it has no info on it at all he's been driving it daily says he doesn't have any issues with it I can tell that it's not correct for one it's got a rough idle as they miss all I can assume why the head was pulled is possibly had an overheat issue and they had to have the head reworked not sure again I was not able to pull any codes on it as I did not have a code reader he wanted 6,500 for it which I'm sure it was worth it I offered him 55 he said he would take it but before I jumped on it I was trying to determine what could be the issue at 5500 I don't think I can get hurt even if I have to have the head removed and rechecked possibly has a burnt valve in it or a valve that's not seated properly any input that anyone can give is greatly appreciated I do not mind buying it in the condition that it's in I would just like to try to get a general idea of what it could possibly be there's only so many things that could be

[metalworker0]

what engine does it have in it , what country are you in ?

all the best..mark