He's probably referring to his catalytic convertor (cat).
But back to his point. I've posted on this before and it may seem like I'm beating this to the ground, but my car went from a nice sporty Z to a tired beat dog dragging it's butt around, so much so that I wouldn't have raced a moped.
The mechanic who restored my baby showed me the culprit, after I had taken the car in to get fixed properly. Inside the distributor is the vacuum advance plate that moves the rotor.
This plate is plastic and holds several ball bearings. After years of heat and use it gets brittle and breaks. In my case I had ball bearings all around the distributor which probably didn't help at all. Anyhow, when this thing breaks, it usually throws your timing off, that's because the vacuum advance that has occurred now cannot return to the proper setting. When you accelerate again, you create more vacuum and once again it may / may not actuate the advance mechanism and once again it messes up your timing.
The ONLY fix is to replace it.
With a new one, apparently still available from the dealer, my car is once again fast peppy and if it weren't for the u-joints might burn rubber.