Forget my last post. For some reason when I looked at this there were no responses showing. ???
About all I can suggest is drop by an AutoZone and have them pull the codes. Post any results back here. Sometimes another set of eyes ( but not a diagnosis) can help.
The only other thing I could mention at this point is connecting a vacuum gauge and making sure manifold vacuum is where it should be. This would also show a partially clogged converter. A converter, if partially clogged, should be covered under the 8/80 Federal emissions warranty.
Your car is over the buyback mileage limit so I don’t think you’re going to get anywhere with that, UNLESS you spend a 100 bucks and have a lawyer send a letter.
Sometimes a law firm banner can get some movement.