I have a problem alike i have a 92 civic and i got a b16a2 swap well it was running pretty good until i got jacked for my p28 ecu with the jumper/adaptor harness , well i bought another p28 ecu but this one didnt need the jumpber harness- does that sound right? well now i get a check engine light and it throws out a cell code that its the oxygen sensor. Today i was searching for it in the car and it ends up being that the 02 sensor with the four wire was connected but the other end wasnt plugged in anywhere it was just sitting next to the engine. Well after that i checked the back of the engine before getting to the cat and there was where the 02 sensor goes and there was one but it wasnt connected anywhere. It just had the connector dangling. It does not reach , even tough i make an extension would it still throw the check engine light? And do i need the secondary 02 sensor connected?