one cylinder of a multi cylinder engine and that each cylinder has its own set of intake exhaust valves fuel injectors etc in fig1 an egr system is included in particular egr valve 16 fig1 which can be electrically pneumatically or magnetically controlled is positioned in a recirculation tube that transmits exhaust gas from manifold 52 to intake manifold 42 a method and system are provided for controlling the rate of dpf regeneration by metering the oxygen in the inlet gas to the dpf is described in the above referenced patent application the entire subject mater thereof heaving been incorporated herein by reference the current invention builds on that invention more particularly when the dpf 26 is regenerated the dpf exit temperature is high enough for lnt desulfation to achieve desulfation of the lnt there is also a need to achieve sufficient oxygen depletion of the gas entering the lnt the inventors have discovered the use of an oxygen sensor uego sensor 33 upstream of the dpf 26 to control the dpf 26 regeneration rate by metering the oxygen flow of the gases entering the dpf 26 using uego 33 the inventors have also discovered the use of an oxygen sensor 35 downstream of the dpf 26 to control the oxygen content of the gas entering the lnt 72 the goal is to remove the oxygen from the gas that exits the dpf 26 in general the oxygen content of the gas exiting the dpf 26 will be lower than that entering the dpf 26 since soot combustion removes oxygen by.