Exhaust gas characteristic detecting apparatus for internal combustion engine

摘要

In an internal combustion engine having a double-structure exhaust passage comprised of an inner (bypass) exhaust passage and an outer (main) exhaust passage arranged to surround the outside of the inner exhaust passage such that exhaust gases are discharged through one of the inner and outer exhaust passages, an exhaust gas characteristic detecting apparatus is capable of reliably detecting the characteristic of exhaust gases through the inner exhaust passage. The detecting apparatus comprises a guide pipe extending across the outer exhaust passage and having an exhaust gas introducing port facing the inner exhaust passage for introducing exhaust gases flowing into the inner exhaust passage into the guide pipe, and a sensor having a sensing unit for detecting the humidity of exhaust gases and arranged such that the sensing unit is positioned in the guide pipe.