Hey thanks guys for all the replies! I don't have time to read through them all and reply and ruminate on the subject right now. I'm in the labor pit at the moment. I will later.
...Answer to the first question. The car went to the dealer because I wanted them to check the front bushings. Of course they always run a diagnostic. And of course rather than trouble shoot the cat situation, the service thief just hands me an estimate for a complete cat job then he says I ought to go see his sales manager and get a new one. etc etc etc.
I really hate the dealer because he never seems to be on the side of the customer. I asked him why he didn't offer a line of diagnostic that might uncover a cheaper problem first, he just shrugged his shoulders. 9 time out of 10 the customer will take one of those options that are both most profitable for the dealer.
I'll study this closer later and give some answers to the questions... Thanks again for all the help
have a beer!
BTW I have not lost any power. the engine purrs like a kitten and runs like a cheatah. I use gas from all different sources... I also use middle grade octane... never had a problem but, I hope I didn't do any damage. I'll get the codes read at auto zone. Gootaa get back to work.