i got a 97 hx and been working on it for about 3 months. now it run and havent had a problem with it but doing a tune up and found that the oxygen sensors are switched. the primary/a.f meter is in the secondary spot and vice versa. the primary is somewhere around 300.00 dollars and the secondary is 75.00. so i thought they switched them to save money oh the primary/a.f meter IS NOT plugged in but the secondary one is. it also has a cheap *** header on it which was on it when i bought it(got a new one) can the car run and run good without the primary/a.f meter plugged in? and help from all the honda gurus out there would be great.

 

Is your car 5 speed?

Did the previous owner convert the exhaust system properly? I will assume no. Here is a link going into detail about it more.

https://www.hondacivicforum.com/foru...version-73237/

The primary o2 sensor is not plugged in since the HX has a 5 wire o2 sensor ($300) and the 4 wire that is in there will not plug up. The o2 sensor was put in there to stop an exhaust leak.

 

You need the primary sensor to run right. Without it it won't go into lean burn mode and you won't get the best mpg.

 

i just put a new exhaust on tonight and yea they didnt convert rite but i just did and i have to put the header with all new oxygen sensors primary and secondary so we will see what happens after the install. but it runs good with the secondary only. anyone think they could have rewired it somehow to make it work with only the secondary.my check engine light is on and went off when i did plug in the primary but the car idled wierd surging and almost dieing so i unplugged and it stopped surging and the light went back on. so i dont know.