This a 1988 Honda Civic Wagon 4x4 it has failed the Massachusetts I/M test . 2- Speed idle the HC at idle = 401 ppm HC at 2500 = 800 ppm CO at idle = .82 % CO at 2500 = 8.06% I replaced the O2 sensor it was no good . Also replaced cap rotor wires and plugs . T... Login to read more.