Hi! Since there seem to be a lot of experts for Hondas here on this site and I normally work on european cars I decided to post the Problem I have with my brothers Civic!

The car has 188000 Miles, an is a 1.5 Liter 100hp with an Automatic Transmission.

I got it to run fine after it wouldn't start up because of a soaked main Relay that thanks to you guys I found and replaced.

The Car was parked outside for the last year after it didn't pass smog in '06. The car had an overrich mixture and it still has in a way. I was hoping it to be the oxygen sensor broken but it's not quite that easy, obviously. I had my multy meter and Measured the voltage coming out of the sensor. While idleing the sonsor give a voltage of about 0.5-0.6V which should(! ) be close to okay. But then if I rev up the voltage goes up to about 0.65-0.7V, Then I keep the RPM at about 2500 it should go back to about 0.5V right? But instead after about 5 Seconds it goes up to about 0.8V (which you can actually hear because the engine revs up a little more).
When I open tank of the car after it was running it sucks in air so I thought it may be the (I looked this word up in a dictionary I hope youy know what it is) activated carbon filter that is broken. (its the thing which collects all the fumes from the gas inside the fueltank and then gives them back to the engine while running)

So I hope you guys have enough information to get the picture! I hope somebody can help me on this quick because I only have another week over here in Cal, then I'm back off to europe!

Hi! since there seem to be a lot of experts for Hondas here on this site and I normally work on european cars I decided to post the Problem I have with my brothers Civic!

The car has 188000 Miles, an is a 1.5 Liter 100hp with an Automatic Transmission.

I got it to run fine after it wouldn"t start up because of a soaked main Relay that thanks to you guys I found and replaced.

the Car was parked outside for the last year after it didn't pass smog in '06. The car had an overrich mixture and it still has in a way. I was hoping it to be the oxygen sensor broken but it's not quite that easy, obviously. I had my multy meter and Measured the voltage coming out of the sensor. While idleing the sonsor give a voltage of about 0.5-0.6V which should(!?) be close to okay. but then if I rev up the voltage goes up to about 0.65-0.7V, Then I keep the RPM at about 2500 it should go back to about 0.5V right? but instead after about 5 Seconds it goes up to about 0.8V (which you can actually hear because the engine revs up a little more).
When I open tank of the car after it was running it sucks in air so I thought it may be the (I looked this word up in a dictionary I hope youy know what it is) activated carbon filter that is broken. (its the thing which collects all the fumes from the gas inside the fueltank and then gives them back to the engine while running)

so I hope you guys have enough information to get the picture! I hope somebody can help me on this quick because I only have another week over here in Cal, then I'm back off to europe!
I'd be checking leaking vacuum lines as well - they can give some of the same symptoms...

I would run the car for several miles and check for codes. With the number of miles on the car, the oxygen sensor likely needs replacing--go with a Denso. Maybe this will help:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-46563.html#post223376

I'd be checking leaking vacuum lines as well - they can give some of the same symptoms...

I checked the vacuum lines and they seem okay, I'll try a new oxygen sensor, maybe it'll help.

But there are no further known problems with e.g. leaking injection or something like that? Or maybe a start-up (! ) injection nozzle that keeps on running?

How and where do I read codes on this car?

Thanks!

See if this helps:

https://www.askmehelpdesk.com/cars-trucks/reading-error-codes-92-95-civics-obd-hondas-18139.html

See if this helps:

https://www.askmehelpdesk.com/cars-trucks/reading-error-codes-92-95-civics-obd-hondas-18139.html


Hi! So I finally found the ECU under the Carpet, and I guess that the Red LED is the thing I should be looking for right? What it does is that it blinks 16 times (short blinks) and then after a short period it starts over.
What is that supposed to mean? Is it the injection problem? Shouldn't that be one long and 6 short blinks?

No. Not that year. 16 is injector circuit.

Remove the Hazard fuse for ten seconds or longer. That will clear the codes and then run the car for a few minutes and check if that code comes back. It probably will.

One last update: I got some used injection nozzles (both) and took the batterie off for 20 sec. and now the LED isn't blinking at all anymore. The voltage coming out of the Oxygen sensor althogh is still not completely satisfying. Idling its still around 0.5-0.6V although with breakouts from time to time. Reving up at 2000 rpm its hard to make out. But its mainly at around 0.7V going down to 0.4 something every once in a while!

Do you think I can try getting it smogged?

Give the cylinders and intake runners, as well as the exhaust system, time to clear out the extra fuel. If the O2 sensor is working properly, you'd be hard pressed to monitor without an O-scope.

And when you go for Smog test, don't let the Cat cool off. Right before they test try to keep the revs up to reheat the Cat.

Good going! And good luck!

Autozone has a product especially for times like this and especially for cars like this before going through the exhaust emissions test - I think it's call Z99 or X99 - comes in about a 2 oz bottle and supercleans your fuel system and highly oxegenates your fuel so you can get through on the emissions test.
Since you've checked all the obvious, I'd recommend the next step to run some 'Valve Stauber' or a qt of Techron or one of the high quality fuel system cleaners through it - should clean your injectors right enough and help burn away any deposits. Try this before going much further as this is a cheap fix without much effort - I used to do it on my BMWs when they'd start running rough and it was like a tune-up in a can.

Okay one last update:

After exchanging the two injection nozzles by two used ones we got at pick and pull for 26$ the ECU didn't blink any codes anymore so I checked the Voltage on the oxygen sensor again it was still not completely satisfying, but it had improved especially at higher rpms. SO we took it to smog this morning keeping it reved up all the time like captian rich proposed and it passed smog.

Thanks for your help everyone

The final solution to the problem was the two Injection nozzles! The old green one was all black on the front tip the 'new' one looks a lot better already.

Thanks again and see you guys!