Failed SMOG, now what???

Hi, I am trying to sell my 1992 Toyota Tercel, it runs good but has
200k miles on it.

I failed the smog test and now I don't know what to do.

The emission problem could be o2 sensor, catalytic converter or EGR
valve. Or even more than 1 of the 3. So this could cost me a lot.

I was asking $1400 for the car. Now, I don't know if I fix and try to
ask for more, if I should donate, etc...

Do you think I could replace the 02 sensor or catalytic converter
myself? I amnot a mechanic. If the problem is in the 02 sensor or
converter it wn't cost so much, but I believe the EGR valve costs
around $200





Some people are calling me and saying they will buy the car as is. But
I am afraid of that, because without smog they can't transfer to their
name.



What do you suggest?



I appreciate your help.



Thanks so much,