This sounds alright only in the event it's correct. I believe there are
three catalytic converters on this car. Why does the mechanic want to
replace those items? Was the check engine lamp on? If so, what were the
trouble codes? Which of the three converters will he be replacing?
My gut instinct says this won't fix your car. Why? Because the oxygen
sensor doesn't tend to affect acceleration on this model when it fails.
(This doesn't mean it can't do it-- I've seen it happen, but it's very,
very rare.) As for the catalytic converter, if it were clogged, it would
be likely to be *more* of a problem during freeway driving. When a
catalytic converter is clogged, it restricts exhaust flow, making high rpm
performace drop, and in more severe cases, makes it impossible to reach
high rpm or to even start the engine.