Patent ID: 8438841

Claim:
A method for controlling regeneration of a particulate filter of an engine of a vehicle, comprising: during combusting engine conditions, directing exhaust from the engine to a three-way catalyst and then to the particulate filter positioned downstream of the three-way catalyst; during non-combusting engine conditions and while the vehicle is in motion, directing fresh ram-air to between the particulate filter and the catalyst to regenerate the particulate filter, the ram-air introduced by vehicle motion; and during at least some combusting engine conditions and while the vehicle is in motion, adjusting a ram-air flow valve to direct ram-air into an exhaust passage based on a pressure of the exhaust passage being less than a threshold pressure value, regenerating the particulate filter, and closing the ram-air flow valve based on the pressure of the exhaust passage exceeding the threshold pressure value, the ram-air flow valve adjusted responsive to regeneration of the particulate filter.