Ford Repair: Poor performance/ No power, converter error, cat converter

Question
Hi Tony,
I have a 97' t-bird with a 3.8 v6, it was running real rough last week and started to act like it was going to stall at stops. then the "service engine soon" light came on and it was acting like it has no power after I take off from a stop, it is taking forever to get up to speed no matter how much I gave it the pedal. I stopped at an auto store and they did a code check for me which showed 5 or 6 codes pop up. (not in any order) 1. vac. leak, 2. misefire on 3, 3.Cat. converter error (not sure on the wording on that one)4. o2 sensor error, 5. misfire 2 & 4, what the person told me is it looked like it needed a tune up so I started there and replaced the wires & plugs. it did idle and run much smoother and from astop to 35mph it was better but that was it....from 35mph to 55mph it took for ever like it was being restricted from power to get up to that speed. other then what I have listed and told you Im noticed a rattle under the car so I took a look under there and the noise seemed to be coming from the exhaust by the Cat. on the drivers side. ( by the way is there three Cat. con. on the exhaust??...or are the two up by the manifolds the resonators.???. it runs smooth at idle and at the beginning of take off...but after that it goes flat.
any help in this matter is really appreciated

Answer
Hello Nelson, You might have a cat converter restricted, there will be o2 codes with a restricted converter. How much exhaust flow is there? you can drop the exhaust down so the exhaust flow does not go through converter and if it gets power back that will answer your question. Thanks Tony