I picked up a 96 dx hatch about a month ago. I've been having problems with it overheating at idle. It is basically stock except for a pacesetter header, and apexi exhaust which came with it. I checked the fan, the fan on the radiator looks to be brand new. There are no coolant leaks. Trying to figure out why it's overheating.

Also, I just noticed that the O2 sensor on the header isn't actually hooked up; no where on the exhaust can I find a hooked up O2 sensor. I'm not throwing a CEL which that alone surprises me. I don't understand how the car can be running fine with no O2 sensor hooked up. Should I go get a new one and hook it up right away, and why wouldn't the car throw a CEL for a cut/missing O2 sensor?

I was also thinking that might be the cause of the overheating if the car is running really out of tune, I don't know much about D series honda motors, but I'm assuming the O2 sensor is the main part of tuning the fuel map, which without it I would think it would throw a CEL and possible run really lean or rich. I'm going to start by checking the fuses on the fan.

 

anybody have any insight on the no o2 sensor but no CEL and car running seeming fine?

 

check to see if ur fan turn on when it gets hot., could b thermostat buddie, check to see if ur radiator fan switch is plug, an add some antifreeze while your at it

 

probably gonna change the thermostat, but what about the o2 sensor not being connected?, how is that NOT an issue?

 

you are the chosen one its possible who ever owned your car wired it toa fuse with the correct voltage or whatever needed to not throw a code .. but dont hold me to that.

 

are you sure that the previous owner didn't take the check engine light out?

 

I'll check that but the dash seems untouched and I see no extra/different wiring, and the car runs great, an auto, chrips second, and gets 32mpg.

 

that is my one and only O2 sensor not hooked up, but the car gets 32mpg ??? explanation!!!


also, how can I check to make sure my check engine light is working properly?