P0420 Jeep - Can presence of P0420 code result in loss of power, especially at low end ?

Question

Slow acceleration. Idles fine, no misfire detected. No power under load.

Answer 1

P0420 Catalyst system efficiency below threshold (bank 1)

P0420 can be the result of slow acceleration , and no power under load. You have a drivabilty concern , Being a speed density engine the engine uses a MAP (manifold absolute pressure) a faulty MAP will give slow acceleration and no power under load or anything that can affect the MAP performance such as a plugged air filter, even a partail plugged exhuast system. In this situation code cannot be counted on,the basic has to be performed.such as ignition timing, Proper working of the transmission and the transmission fluid condition.