Abstract: A muffler device with catalysts for improving purifying exhaust gas of nitrogen oxides within a motorcycle exhaust pipe comprises a muffler divided into three chambers, a first chamber, a second chamber, and a third chamber; a front exhaust pipe; a front reduction catalyst; a rear exhaust pipe provided with a secondary air inlet behind the reduction catalyst for introducing secondary air therein. Thereby, the exhaust gas from an engine with air-to-fuel ratio less than or equal to 14.7 will firstly pass the reduction catalyst to have its nitrogen oxides (NOX) effectively inverted into nitrogen (N2) and oxygen (O2), and then secondary air will be added to the exhaust gas so as to increase its air-to-fuel ratio to larger than 14.7, and finally the exhaust gas will pass the oxidation catalyst to have its carbon monoxide (CO) and hydrocarbons (HC) effectively inverted into carbon dioxide (CO2) and water (H2O).

Abstract: A staged electrode carrier of an O2 sensor comprises a sensor; a detecting end carrier installed in the sensor; the detecting end carrier having a positive lead, a negative lead and a channel communicated to atmosphere; one end of the positive lead of the detecting end carrier having a positive interface exposing in the channel so as to contact the atmosphere and one end of the detecting end carrier having a negative interface exposing from an outer wall of the detecting end carrier to contact gas to be measured; and a transferring end carrier installed in the sensor having a positive lead and a negative lead. A detecting end carrier is made of zirconium oxide, and a transferring end carrier is made of Al2O3, CaO or MgO.