90 civic with zc HELP FAST

Ok have a 90 civic hatch with zc.. great so far...But just got a ticket and have less than a month to inspect...Now the check engine light comes on after it kind of warms up....I checked the ecu and giving me i believe and o2 sensor code..when i swaped the motor i had a pretty new o2 sensor on the old mootor so i just took it out and put on the new header i bough off ebay(pretty good buy)....the o2 sensor on there i had bought from auto zone or advance auto..so i had to cut and attach...to make work..cost about 20 bucks...not to sure...today thinking of going to junk yard and getting a factory honda one....So please guys and gals any help would be great...have less than a month court date on 20th on nov.......Have one more issue too, fans turn on ass soon as engine turns on, always on, but does turn off when car turns off....changed fan switch not to sure which one i used civic or integra one also went to yard and took some relays and changed them and all that did was made the condensor fans stay on with the main fans...in summer time , temp guage would go up at high way speeds....Sorry for the lenght of the thread.......

That ZC is obd-1 correct? Take a look behind the block on the firewall side for a plug thats not connected, its large and has two prongs in it. My engine is obd1 as well and since the fan switch was relocated on these blocks and the plug itself changed mine was simply shorted by running a wire to each prong and shoving a ball of aluminum foil into the plug. The fans run whenever the key is on. If this is your case and you want to fix it then the fan switch is on the thermostat housing just under and behind the distributor.

The fans coming on with the car shouldn't be an issue, alot of us do that anyway. If you want to fix it, Frodo told you where the switch was.. or you can get a generic temp switch for it, and run that inline, just strap it somewhere close to your block.

As far as your o2 sensor, I dunno really what to tell you about that... but always remember.. most of us are pretty nice here, and we read just about EVERYTHING that comes up... so if I didnt' answer this post before, that doesn't give you the right to PM me about it... if I was able to help you, I'd have posted already.

(PM to Dr0pZ0n3) Check my post fam maybe you can help me....

One reason why the fan would come on with the ignition is that the fan motor is grounded to the chassis. I had my black ground wire spliced from the fan motor to the chassis by the radiator support. I never had an issue with it. The A/C relay and fan wires were sorta hacked when the A/C was removed prior to me owning the car. So I wired the fan from the factory wire with the ground spliced to the chassis and it worked fine...

if i remember correctly i don't recall anything not being connected.... but i'll look once again.........and someone says it's fine but on the highway that needle rises in the summer now that it's cold , not getting that, so my just deal with it in the summer...

Replace the thermostat, your needle should go lower on the highway due to more airflow.. Especially if your fans are on all the time.