90 348TS

Getting ready to go pick up this car in the next week or so. Question on some ECM codes that are on now. The car starts up really rich and a little rough and takes a few minutes to start to settle down. Car drives fine, but both bank code lights are on. They said they swapped the MAF's and the problem went away, but then now both banks are on. Likely the problem is the MAF's unless a coolant temp sensor? Are there 2?

Also, is there a way to read the codes manually without having a scanner? And also, is there a way to clear the codes without a scanner. I read you could clear the codes by disconnecting the battery. Just wanted to make sure if the mechanic working on this car before we buy fixes or thinks the problem is fixed, disconnects the battery it will go away or how long before it would pop back up so we indeed know it's fixed perfect. Not doubting the seller or anything just making sure we all knew it was good to go.


Thanks!
Amir