said by jsears8:Forgot to mention I replaced the 02 sensor as well.
You know there is two sensors, right? One before the converter and one after. The DTC you have basically means that the values the computer sees when comparing the two doesn't match what it should be, based on the current operating of the system. The post-converter sensor should be porportionally less then the upstream. For instance, if the cat is shot, then the value won't vary as much as it should. Or if you have a exhaust leak it may vary too much.
said by jsears8:Im trying to avoid taking it to the dealer or shop in fear that they suggest replacing things that are not the cause, and im back in the same boat.
Right. Because you replacing "everything that [you] could think of, including Cat, plugs, wires, distributor, battery," and O2 sensor was real cost effective at solving the problem. Any one of those repairs (plugs and wires I'll combine) probably cost as much as what the diagnostic charge will be. If you don't want to chance playing swap-a-part, just tell them you want it diagnosed but not to replace anything without your authorization. You have complete control.
And does your car even have a distributor? Maybe the carb needs cleaned out too.