Two issues 1-check engine code of P0315 and 2-very low idle at stops.

I had a check engine code of P0135 I cleared the code with my computer. Start the car up and light comes back on right away. Clear the code with the car running and the idle has a slight change... a few seconds later the light comes right back on with a very slight drop in idle. I repeat the process about 5 or 6 times with the same outcome everytime. This tells me that the o2 sensor is in fact faulty and I replace it. I clear the light and it goes out and stays out. As soon as the car goes into the closed loop cycle for emissions (when car is warmed up) it starts with the very low idle at stops. I no longer have a check engine light on but still have the low idle symptoms
I replaced the o2 sensor with a Bosch from Auto Zone... have there been any issues with Bosch over the Denso(sp?) sensor? I'm leaning towards the catalytic because I'm not getting any other codes but it only happens when warmed up.?. I don't want to just start throwing $ and parts at it.

Thanks

 

"Low idle" is subjective. Don't trust the dash tach to indicate idle speed accurately. Does it ever stall? If you engage the A/C does it idle up slightly and the compressor keep running? Also every time you reset the computer, you need to drive for a while for it to recalibrate. During this time it may not run very well.

You're definitely barking up the wrong tree thinking a cat can cause this.

 

I was checking the idle through my computer...It runs down to about 400rpm and stays in that area once warmed up. It runs great when cold.
I haven't tried it with the A/C on but I will.
When you say drive it for a while does that mean 5-10 min or a 1/2 hour or more to reset the computer?
I have had bad cats in the past but they give you problems while acclerating as well as at idle.
Thanks I think I will try the reclaibration idea first.

 

i have a 2000 civic ex and your suppose to idle about 600 to 650 might be a vaccum leak but i really dont know head to autozone and let them look up that code for you or call honda and they could tell you what that code means but yah drive your car a little bit and call honda and once you find out what is shooting off that code fix it and you should be done

 

Thanks for the response
I have my own matco computer and the code I got is for the primary o2 sensor which I replaced and the problem still persists. From the reading on my computer I'm idling at around 400rpm or so when the car is warmed up.

 

So I took the civic out for a 15-20 min. run to try and get the idle to reset... no luck. There is no real difference with the A/C on or off.

When the car is cold it idles at 1000-1100 rpm after warm up it runs just above the zero line (which on my computer it was 300-400 rpm) if I sit and let it idle long enough it will climb 100 rpms or so. Where would you go next? I know cars just not the specifics of the civic.

I have done some searching about this on the internet and it seems like there are a lot of people that have the problem but no one has stated a solution to the problem? Is this a common issue with the civic or hondas in general?

 

Would a High Idle Valve be capable of causing these kind of symptoms? Or would it only affect things if my car was idling too high?

2000 civic EX
4 cyl.
80,000 mi

 

I think many have cleaned out their IACV in situations like your and also some recommend adjusting your idle so that it goes up to 650 or so w/o A/C.

It is disconcerting to know that it isn't going up with the A/C on. It should jump about 100 - 150 rpms.

I doubt this is a vacuum leak problem however. Apparently with the civics running a MAP system, a vacuum leak would result in excessively high idle, not low.

 

I found a how to in the DIY section of how to clean the IACV... I don't think I see the same picture. Would you or anyone know where the IACV is on this 2000 civic? It's not my car or I would have a service manual to tell me these things.
Thanks

 

you can go to the link in my signature and download the 96-00 service manual in pdf form. it should tell you where it is.