A method of calculating a nitrogen oxide (NOx) mass reduced from a lean NOx trap (LNT) during regeneration includes calculating a C3H6 mass flow used to reduce the NOx among a C3H6 mass flow flowing into the LNT of an exhaust purification device, calculating a NH3 mass flow used to reduce the NOx among a NH3 mass flow generated in the LNT, calculating a reduced NOx mass flow based on the C3H6 mass flow used to reduce the NOx and the NH3 mass flow used to reduce the NOx, and calculating the reduced NOx mass by integrating the reduced NOx mass flow over a regeneration period.

An exhaust purification system comprising an exhaust purification catalyst, a downstream side air-fuel ratio sensor, and a control device performing air-fuel ratio control for controlling an air-fuel ratio of exhaust gas and abnormality diagnosis control for diagnosing the downstream side air-fuel ratio sensor. In the air-fuel ratio control, the control device alternately and repeatedly switches the air-fuel ratio of the exhaust gas flowing into the exhaust purification catalyst between a rich air-fuel ratio and a lean air-fuel ratio. In the abnormality diagnosis control, the control device judges that the downstream side air-fuel ratio sensor has become abnormal when the air-fuel ratio of the exhaust gas is made the rich air-fuel ratio by the air-fuel control and the output air-fuel ratio of the downstream side air-fuel ratio sensor changes from an air-fuel ratio richer than a predetermined lean judged air-fuel ratio to an lean air-fuel ratio.

An apparatus sizes an exhaust component that includes an outer shell that surrounds first and second substrates. At least one sensor hole is formed in the outer shell at a location between the first and second substrates. A first end of the outer shell is surrounded with a plurality of first fingers to size the first end around the first substrate to a first cross-section. At least one first finger has a protruding portion at a first finger distal end that is longer than first finger distal ends of the other first fingers. A plurality of second fingers surrounds the second shell end to size the outer shell about the second substrate to a second cross-section. At least one second finger has a recess portion at a second finger distal end that receives the protruding portion of the at least one first finger.

Methods and systems to control a temperature of a selective catalytic reduction catalyst are disclosed. In one example, a diverter valve that includes two butterfly valves that are coupled together via a shaft is adjusted to control a temperature at an inlet of the selective catalytic reduction catalyst so that the selective catalytic reduction catalyst may operate efficiently.

To keep medium purification efficiency at a high level and prevent deterioration of emission performance. An aspect of the present invention includes: a downstream equivalence ratio calculation unit that calculates a catalyst downstream exhaust gas equivalence ratio by using a catalyst statistical model that receives at least a detection value of an air-fuel ratio sensor on an upstream side of a catalyst and outputs a catalyst downstream exhaust gas equivalence ratio; an oxygen output calculation unit that calculates an output value of an oxygen sensor by using an oxygen sensor statistical model that receives the catalyst downstream exhaust gas equivalence ratio and outputs an output value of the oxygen sensor on the downstream side of the catalyst; a downstream equivalence ratio correction unit that corrects the catalyst downstream exhaust gas equivalence ratio calculated by the downstream equivalence ratio calculation unit based on a calculation result of the oxygen output calculation unit and the detection value of the oxygen sensor; and an air-fuel ratio control unit that controls an air-fuel ratio of an air-fuel mixture of an internal combustion engine based on the corrected catalyst downstream exhaust gas equivalence ratio and air-fuel ratio target value.

A method is for route identification that is conducive for successful diagnosis of an exhaust gas treatment system of a vehicle. In the method, an ECU in the vehicle receives a value of GPS coordinates from a GPS module, and the ECU retrieves a value of day, date, and time from an ECU clock. The ECU monitors a value of engine operating conditions with reference to the received value of GPS coordinates and the retrieved value of day, date, and time. The ECU identifies a segment of GPS coordinates for successful diagnosis of an exhaust gas treatment system based on the monitored value. Upon the identification, the segment of GPS coordinates is stored in ECU memory.

Methods and systems are provided for continually monitoring a functionality of an exhaust catalyst based on roll-down of a monotonically decreasing catalyst activity parameter representing catalyst storage capacity. Catalyst degradation may be indicated responsive to the estimate of catalyst storage capacity lowering below a threshold. Engine operating parameters may be adjusted based on a current level of catalyst storage capacity.

An assembly for determining lambda values of an exhaust gas of an internal combustion engine is provided. The internal combustion engine is attached to an exhaust gas treatment device with at least one first catalyst and a second catalyst. Additionally, the assembly has the following: a first lambda sensor in a first removal line, wherein the first removal line is designed to remove a part of the exhaust gas upon entering the first catalyst and conduct same back into the exhaust gas treatment device after the exhaust gas passes the first lambda sensor, and the first lambda sensor and at least one part of the first removal line are arranged outside of the exhaust gas treatment device; and a second lambda sensor in a second removal line, wherein the second removal line is designed to remove a part of the exhaust gas between the first catalyst and the second catalyst and conduct same back into the exhaust gas treatment device after the exhaust gas passes the second lambda sensor, and the second lambda sensor and at least one part of the second removal line are arranged outside of the exhaust gas treatment device.

A method for heating a catalytic converter in an exhaust system of an internal combustion engine, in which an exhaust gas burner for heating the catalytic converter is arranged, upstream of the catalytic converter. A lambda probe for controlling the combustion air ratio of the exhaust gas burner is arranged immediately downstream of the exhaust gas burner and upstream of the catalytic converter. The method includes operating the internal combustion engine with a stoichiometric combustion air ratio (λ.sub.E=1), activating the exhaust gas burner, which is operated alternately with a substoichiometric combustion air ratio (λ.sub.B<1) and a superstoichiometric combustion air ratio (λ.sub.B>1), wherein from the substoichiometric combustion air ratio (λ.sub.B<1) to the superstoichiometric combustion air ratio (λ.sub.B>1) as soon as a rich breakthrough is detected by the second lambda probe (34), and wherein a switchover from the superstoichiometric combustion air ratio (λ.sub.B>1) to the substoichiometric combustion air ratio (λ.sub.B<1) takes place as soon as a lean breakthrough is detected by the second lambda probe.

A catalyst deterioration diagnosis apparatus includes an upstream side air-fuel ratio detector, a downstream side air-fuel ratio detector, an air-fuel ratio variation integrator that integrates the output variations of the respective air-fuel ratio detectors when a diagnosis running condition is satisfied, and a determiner that determines catalyst deterioration when the output variation integrated value of the upstream side air-fuel ratio detector exceeds a predetermined integration ending threshold, and further when a ratio between the output variation integrated value of the two detectors exceeds a predetermined determination threshold. The air-fuel ratio variation integrator holds the integrated values when the diagnosis running condition becomes unsatisfied before the integrated value of the upstream side air-fuel ratio detector reaches the integration ending threshold. The air-fuel ratio variation integrator resumes the integration using the held values as initial values when the diagnosis running condition is satisfied later again.