its 90 crx si, 223,000 miles w/ dohc ZC engine (not sure miles on ZC)

i've had check engine light come on occasionally for several years, and checked ecu which showed a code1, which means replace oxygen sensor.

i just assumed for some reason to replace that O2 sensor thats in front near exhaust manifold, but after thinking about it, i did'nt know if it meant to replace that one only?? or to also replace 2nd O2 sensor, thats underneath the car by catalytic converter (not familiar with that one as much) ??

does anyone know what code1 means exactly ?? like how many O2 sensors are there and which ones are you supposed to replace if you have a code1 ???

any info would help

thanks

 

My dohc zc's o2 sensor started doing it too lately. I assume its the one on the header in the front side. Since its the only o2 I have and that o2 has been used for like six years on another car. But ya I'm getting mine switched soon hopefully so ill let you know if I get it changed first. Good luck fellow zc'er!

 

i think when they did my ZC swap that they just used my original 90si exhaust manifold, along with the O2 and all that................ i'm pretty sure, cause i remember how the original 90si manifold does'nt line up correctly to the exhaust port holes on the zc engine.


but yeah, thanks for the reply, and if you find out let me know if the code1 means that you replace both front and back O2 sensors.

 

U only have one o2 sensor. If the sensor goes bad it doesn't usually throw a code. Just make sure its plugged in all the way then Try resetting the ecu by removing the ecu fuse under the hood for 30 secs

 

oh ok, thanks for confirming theres only one O2 sensor, i just read some post one time where someone said there was a second O2 sensor somewhere under the car by exhaust or something, but they probably just meant (exhaust manifold), so i just mis-read it.

why do you say that if the O2 sensor goes bad that it won't throw a code ??

then why would it say in the helms manual that if you have a check engine light, and your ecu has a code1 then that means to replace O2 sensor ???

if it does'nt throw a code when O2 sensors go bad then how would people know O2 sensor is bad?


my O2 sensor is in so tight that i could'nt knock it loose even though i tried everything i could, i just could'nt get a grip at the angle with the tools i had available, and i did rent the O2 ratchet from autostore but since i could'nt get the O2 sensor off i returned the rental tool.

and you said to just make sure its plugged in good and then just reset ecu,

i know its plugged in more than good,

and i don't really want to just take the easy route and keep using the same old O2 sensor and just reset the ecu, i mean this O2 sensor probably been in the car for as long as i can remember, cause i've never ever replaced an O2 sensor or had shop do it either, and i have had this car 12 years, so would'nt you think its safe to say its time to replace it??? i would feel better doing so, plus i'm hoping it might improve MPG and performance some too.

 

LOL what?
a car not throwing a CEL for an 02 Sensor...... LOL

 

Just replace it then. It's only $18 if you buy the universal bosch 1-wire from Autozone. Yes, it will throw a code if the o2 sensor is bad. However, other things will through that code as well. Mine would through the code everytime I had to slow down because the person in front of me was driving slower and I would just let off of the gas and the the engine slow me down. The light would come up like that everytime especially during the summer. It wasn't until I got it tuned did that stop happening.

 

With that many miles on your O2 sensor, it may be bad and time to change it, but if it is doing its job correctly of monitoring your emissions and has sensed a problem beyond the ECUs parameters of adjustment it will throw the code. Just be prepared to check your timing, your cat, or something fuel related if the new O2 sensor throws a code.

 

damn i just learned alot i also have a code1 and was gonna replace my o2 but ima check everythinf else out

my o2 is only 1 1/2 old :/

 

Ya it should definitely throw a code but mine wouldn't budge lol I think I'm going to it a new header then buy an o2 for it. Then My o2 sensor socket stripped it but mine comes on every now and then its annoying. What else causes a code one? Thought it was only an o2

 

thats what im trying to figure out

 

Yupp from my experiences I've never seen a code 1 from a bad o2. Mine had the metal cover broken off and the only symptom was running rich

 

alright, i understand it more now, thanks for the opinions

so now i know theres just one O2 sensor, and that its probably good idea for me to replace it since its so old.


now i wanted to switch to another topic, which is i need help on ways to remove the old O2 sensor??

cause i already had bought a new O2 sensor a while ago, and rented an O2 socket wrench piece from autostore, and i fooled with it for a while and tried all kinds of angles and tool combinations, but in the end i just could'nt knock the old O2 sensor loose!!!!

i took the upper radiator hose off and moved out of the way and reached both arms down in area by the radiator & condensor fans, and i put a socket extension piece on and held the O2 socket piece onto the O2 with one hand and with other hand tried to turn it loose with the best grip and strength i could get, but the angle just made it difficult.

i used PB Blaster also, did'nt help, i'm sure theres ways to use breaker bar or whatever but i coul'dnt see how it would fit, its like you have to have a big "L" shaped tool combination to get the O2 socket piece to reach the O2 sensor, cause has to go down and then over towards the side and onto the sensor, and those socket extension things are wobbly even though they are attached, they swivel around sort of.

i was going to call and see how much shop would charge just to get the O2 sensor loosened for me, and to just gently screw back in, so i can go home and continue finishing the rest myself.

but i would really be curious to hear in detail the various methods people out there used to get their old O2 sensor off ??

 

Sounds like your O2 is in the same place as on my ZC, that real pain in the *** place on the inside of the exhaust manifold in the hardest to reach place. Would it have been so hard for Honda to put it on the side or top of the manifold?

 

crows feet FTW

 

i know, its a tight area to try and position tools and try to get any kind of strong grip on it.


i first started to take the exhaust manifold heat shield off, and i took the bolts near top of it off and there was one in middle too, but then it still was'nt able to come off ??, and then after looking around i see that theres another bolt or two way at the bottom right before the manifold curves back towards underneath the car,

but i could'nt see any way of getting anything in that tight spot where the bolts at bottom of heat shield were, something was right up against it making it a real tight spot, and so i just did'nt take the heat shield off.

but once i started to try fitting socket onto O2 sensor i realise that really it would'nt matter if i took the heat shield off or not, cause the exhaust manifold pipes take the same shape and space up as the heat sheild anyway, cause it just lies right under the heat shield.

one thing i guess i could of tried was jacking car up on all 4 jackstands and try getting at the O2 sensor from the bottom or something like that ?? maybe it would be a better angle or something??

 

my civic obd0 jdm dohc zc with turbo.and i already remove catalytic at my car. .

i m using engine Management piggyback w/Tune .now i want install LC-1 with wideband sensor.

my problem is the 2nd 02 sensor. can i just release the 2nd sensor to my wideband sensor and need to relocation or not?