Or it is running very rich, due to a bad ecu ect sensor, a atuck open injector, or a leaking injector. This can melt the cat and clog it, causing the loss of power. A clogged cat/blocked exhaust can be pressure checked. Drill a small hole in the pipe ahead of the cat and check the pressure. Google search how much pressure you will see with a clog - iirc, a pound or two is all it takes to decrease power.

Not responsible for advice not taken...