Purchased an ECU from Kenji, who's been very helpful! :thumbs up: plugged in
his ecu by the aid of his obd2-obd1 harness, and tapped about a 3' small
piece of wire to the 02 signal so that I can wire my A/F gauge to that wire.
I run my car for about 20 min, and I throw a Code 1. Reseted it again, and
again, "primary o2 sensor"...Spoke with Kenji about the problem and he had
told me to run without the A/F gauge to see if I get a MIL. It's been 3 days, and not a check engine light has gone off. Does anyone know what can
be causing this? Anyone ever had this problem?

 

im know nothing of electronics, but I believe the sensor will cause a thrown code when a certain voltage is reached. Maybe you have a short somewhere in your AF gauge circuit.

 

I really doubt it. I really don't know. im stuck anyone else have an idea on what's causing this?

 

run a volt-meter off the signal wire for a few days and see what happens.

 

Check your ground for the gauge. Seems like it has to do something with the A/F meter. If it runs fine without it, then it seems like the A/F is the culprit. Good luck.

 

would a poor ground actually cause a code 1 MIL? The gauge is working properly...

 

Do what JDM LUDE had said. It could be that the A/F gauge is robbing the O2 sensor or ECU of a certain voltage requirement.

 

JDM lude, i am getting good continuity when i checked the wire..and how exactly would I run a voltmeter on the 02 signal while im driving? and what would be a bad reading? and if i am getting low signal or a bad reading, what would the cause of the problem be?

 

acuraracing...that is exactly what I think is happening with my situation. But why? I've seen numerous of people with AF gauges using the 02 signal and not one of them ever had problems like i am facing. Do you think that if I tap into my 02 sensor wire itself that it would be ok?

 

Ok, so far these are my findings...I just got back from testing the voltage on the o2 singal wire. and the results are...

without the AF gauge, I am running .539-.542 volts, which i think is the correct signal, as per HELMS. When i connected the AF gauge I am getting .993-.996 volts, which i think is not good. Moved the ground to another ground source just incase its ground problems, and still the same voltage b/w 993-.996 volts. Anything else I can do to isolate this problem?

 

as per JDMLUDE, he thinks that somehow the AF gauge is sending extra voltage to the ecu therefore causing my ecu to throw a Code 1. anyone else can share light into this matter?

 

just borrow either mine or dre's a/f gauge. see you @ steve's

 

is your air fuel gauge powered off of anything else, or do the O2 wires power it as well? because some thing is obviously interfering if your voltage almost doubles. Do what all those guys say and try someone elses A/F gauge.
.9 is the highest voltage that the ecu takes before throwing the code, incase you didn't know.

 

thanks bro, didn't know that... as for my wiring. My A/F gauge shares the same ground and 12+ as my oil pressure. But as per JDM lude, I've re-wired my A/F gauge so that it's by itself and still the same voltage at .9 at the harness on the 02 signal wire. Bad A/F?

 

 

sounds like a bad af gauge. let us know what happens.

 

what kind of a/f gauge is it?

 

nah, I'm pretty sure the O2 will take higher than .9...maybe like .999(not to nit-pick)...my a/f meter is actually just an lcd of the voltage from the sensor, no gauge, just straight-up numbers .875 is 13.5:1, or around there...I see above ~.95 sometimes when I turn it on and it's REAL cold out. Totally agree with the diagnosis, though.

 

I'm glad someone knows that the Honda ECU takes the O2 reading out to 3 digits.

This is why those A/F gauges aren't the greatest, but certainly useful. The gauge is displaying a range of about 1V. Since there are typically 10 LED's, it takes about .1V to light up the next LED on the scale. (20 LED's = .05V, 30 LED's = .025V and so on....its makes the daisy chaining of LM3914's useful. And if you didn't know, this chip is whats used on just about all a/f guages. Go to National Semiconductor for more information).

So huh, anyone else see a problem?

 

Autometer....
and sometime this week, im going to use one of my friends A/F gauges to see if my gauge is the causing the thrown code. I'll let you guys know, and thanks for all the help!

 

I would say bad A/F meter. If power is connected with the same power source as the other gauges, then that is ruled out.

Try another gauge like everyone else says.



[Modified by Shft@9GSR, 6:38 PM 4/18/2002]

 

If I do find that my AF gauge is at fault, how good is Autometer with their warantees? Purchased it around christmas time, which is not even close to 1 yr

 

call autometer, they should be good for it.

 

Maybe you are right about the .999 ion_four, but if you mean that you see readings that high right when you turn the car on without getting a trouble code, it could have something to do with the ECU being in open loop mode for a few mins while the car warms up. The O2 sensor doesn't even produce voltage untill it is at like 600 degrees F, so you could see something else happening, but I'm not sure. Whatever the case I want to know what the problem was, when ever SLPMDE01 finds out.

 

Hopefully I'll find out this weekend if my af is at fault or not. WOTM_EJ6?? What do you mean about the ecu being in open loop mode? Do you think it could be the ECU?