i have just gone through a hairball honda experience and need a bit of info to get prepared for my cal smog testing. i got my notice for smog testing and with-in a week my check engine light came on. i have a code reader and it revealed that it was pre cat 02 sensor. easy enough right? not exactly.

as i removed the manifold shroud from my 97 civic lx to get to the sensor with a 22mm open end wrench (to avoid need the 02 socket) i found a crack in the exhaust manifold from the 02 bung. as you may be aware the cat and manifold are one unit. i was pissed.

i removed the cat/manifold unit and had it welded for a mere $60. i thought that the 02 sensor might still be good so i tried the old one after the weld and reinstall, no dice. got and installed the new sensor and the check engine light went off.

the idle of the car was very low when the manifold was cracked, as expected. only problem is that with the new 02 sensor and welded manifold i am still experiencing the low idle. can anyone enlighten me on how to adjust the idle on my 97 5-speed civic lx? the idle remains so low that i am afraid it wont pass smog. not engine dies, or generator light on low, but 450 to 500 rpm's.


tia

 

The easy fix would be the idle screw adjustment on the throttle body.

-Shane

 

sorry i was not more specific in my question. i was looking for the location of the idle screw location. sorry my bad.

lets say i am facing the car with hood open for right and left bearing. which side of the throttle body? and where is it?

tia

 

maybe before messing with that screw, you should try and reset the computer. sometimes after resetting the computer things get fixed by them selves. they actually put a plug so that you dont tamper with it.

 

i have disconnected the neg side of the battery to get the check engine light to go off prior to installing the new 02 sensor. my code reader now shows no code faults. is this not an effective way to reset the computer?

i only ask because on my 99 toyota tocoma this neg battery disconnect reset the computer.

any help on locating the idle adjustment screw still welcome.

thanks again guys for your insight.

 

Is your motor the one that has the down-draft tb? If so, then I am not sure. If it is side draft tb, the the idle adjustment screw will be on the left-top side of the tb. If this hasn't been answered by the time I get home, I will look in my Haynes and find out for you.

-Shane

 

Was your engine idling fine at one point in time?

Did you use an OEM O2 sensor?

 

it idled fine prior to the CE light coming on and discovering the crack in the manifold. i got the bosch pre cat unit, not the OEM.

not sure about the top or bottom draft TB. it is the lx 1.7 5 speed if that helps in the leaset.

thanks, you guys efforts to help have been awesome.

 

Yeah - Bosch O2's aren't the greatest for OBD2. Did you have to splice into the harness to make it work or did it come with a connector already attatched. Are you sure you have a 1.7l and not a 1.6l?

If it was idling fine before the code, the idle speed adjustment screw is not the answer.