What's up everyone. I know this is an old thread, but, you know how it is. I read what the last post said about lean fuel/ o2 sensors. I have the same "code 1"problem." Oxygen content". I got started getting that code probably like a month ago. I've overlooked all connections and possible culprits since then. I replaced the o2 sensor a long time ago when I first got the Rex. And I thought maybe it's not that. But failure with everything else led to me replacing it again the other day. Cel still comes on. And it's not always on. Comes on while driving. Normal or heavy driving. What I did notice is it comes on when I give the car a little more if not like half throttle. Going up a hill or just going faster. I'm telling you guys this so you have an idea of when it comes on. It's not at idle or anything. I could let the car sit there and it won't come on at all. I thought maybe a loose or dirty connection. A short, or even a bad ground. In relation to what the person before me said about a leaky fuel injector is what caught my attention to post. My #1 injector seems to be a little "leaky". You can see it around the injector. Could this related to the problem code1?? In the Haynes manual it list what it coul d be, insufficient fuel being one I them. What you guys think?? Should I go scavenge for some injectors?? This problem is really been on my nerves. The cel more I think. Every time it comes on,I ****ing frown- no joke. Let me know what you guys think. Anybody's and everybody's opinion and ideas are more than appreciated. Someone else experienced this?? Any input is great!! Thanks to all

 

O2 CEL is a result of the ECU getting bad readings from the O2 sensor.
Since you replaced the sensor, you can try replacing it again in the case that maybe you were sold a bad O2. It happens.

If that doesn't fix the problem, then your O2 is detecting some really bad O2 content. This could be anything from a leaky/clogged fuel injector, clogged air filter, vacuum leaks, poorly modified ECU tune, broken valves, etc.

 

Leaky or clogged injector?? Makes sense. How would an injector get clogged though?? Fuel rail?? I will overlook the things you mentioned. Thanks. Will post upany results.

 

my CEL went away after putting my new O2 sensor, i made sure to reset the ECU and stuff just to make sure it adjusted to any changes,

but yours might have something to do with your air/fuel ratio problem ?, like too much fuel etc . . .? so might have to figure that out first, try putting fuel injector cleaner in ?

do you need to replace your fuel filter ? do you have a chipped ecu that has more aggressive fuel maps on it ? is the wiring around where the O2 sensor connects good condition ? i don't know much about this type of stuff, just trying to throw some ideas to check out there

 

I think you're right. Might be a fuel /air problem. I've been meaning to check the injectors out, but the past weather didn't give me a chance. The car seems to be wasting more fuel than usual. The only thing I can think of with the o2 connection is that I quick-connected another plug. The original one snapped off the harness probably from age. Quick connect and taped it up. Didn't think that would be causing the problem. Any input on that anybody?? As soon as I can I'm going to check out those injectors.

 

you sure you used the right type of O2 sensor?, and that the wiring that it goes to is'nt messed up? and did you attach the O2 to that little bracket that holds it in place?

i ended up messing with the O2 sensor way more than i should of, just to put a new one on, in the process, the wire coming out of the end of the new O2 sensor snapped right clean off of it !, so i could'nt use that one, and had to buy another one, also the plastic clip that it plugs into on the harness on other side broke so had to get that plastic piece and splice it back to the wire, finally i had it on and working.

before putting the new O2 on, i failed state inspection, they said it was running too rich, but after putting the new O2, it still failed inspection again, and they said i needed a new catalytic converter, i think the one i had was the original one that came on car, which was 22 yrs old, so i got a new catalytic converter, also i cleaned out the throttle body, and cleaned out the EACV and put new gasket for it, adjusted the throttle cable linkage, then adjusted the idle til it was steady, and cleaned air filter and put fuel injector in, then i passed the inspection.


below, i copied and pasted off a website, that had list of different things that can cause to run too rich, read through them to make sure its none of those things ?


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the air-to-fuel ratio could be off balance due to different things :
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first, pull your sparkplugs and check condition and color of them, compare to one of those charts that show all the different ways the spark plug condition looks and says what the problem is that can cause it to be that way.

when Oxygen sensors fail, they cause the car's computer to improperly adjust the air-to-fuel ratio, and cause the engine to run rich.

Catalytic converters work to expunge exhaust gas from harmful byproducts of burned fuel, and because of this, they can sometimes become clogged, backed-up or otherwise rendered ineffective. This will throw off the air-to-fuel ratio, causing the car to run rich.

Check your timing and make sure your cam gear didnt slip a tooth, cause off timing can cause a more rich firing pattern.

cars use the ECU computer to manage and regulate the engine, sometimes problems can occur with the software that runs the car's computer, causing a variety of problems.

Timing belts can become stretched out over the life of the engine. It's recommended to change them every 50,000 to 75,000 miles. when they stretch, the timing of the engine's camshafts is misaligned with the pistons, leading to either unspent fuel or not enough air.

has it been a long time since you ever replaced the fuel filter with a new one ?

try resetting the ECU, so it adjusts to any recent changes done to car

 

My CEL just came on this morning on the way to work. The engine didn't seem any different, it ran just like normal with the CEL on...

My Civic was in the shop over the winter. I replaced a lot of stuff. New head, valves, timing belt, cam, tensioner, O2 sensor, main relay, thermostat housing, and water pump. Checked the hoses, everything appears ok...

I've only been driving the vehicle for about 3 weeks. It's been running great - I've been getting 40-45 mpg.

I filled up last night at a station that was questionable, could it be bad gas?

Essay0ns

 

go make a new thread. Your question has nothing to do with what this post is about.