Patent ID: 7370472

Claim:
A method, comprising the steps of: sensing an input pressure pulsation wave of exhaust gas at a location associated with an exhaust gas input portion of an emissions trap and generating an input pulsation signal representative of the input pressure pulsation wave, sensing an output pressure pulsation wave of exhaust gas at a location associated with an exhaust gas output portion of the emissions trap and generating an output pulsation signal representative of the output pressure pulsation wave, determining a transfer function of the emissions trap based on the input pulsation signal and the output pulsation signal, the transfer function being representative of loading the emissions trap, and regenerating the emissions trap if the transfer function satisfies predetermined regeneration criteria, wherein: the determining step comprises transforming the input pulsation signal and the output pulsation signal to a frequency domain, and the regenerating step comprises (i) determining a change between the frequency content of the input pulsation signal and the frequency content of the output pulsation signal and (ii) regenerating the emissions trap if the frequency content change satisfies the predetermined regeneration criteria.