arite well ive been searching my *** off all night trying to find an answer to this question that seems pretty damn simple, i duno why no one has this info

all i need to know if how much current is going through the o2 sensor wires that go to the ecu (wire d7 and d14)

im abuot to attempt to make a little a/f ratio control panel using resistors and i cant calculate a range of resistance to try without knowing how many amps im dealing with...

also if anyone has any suggestions on how to wire it i would appreciate it. im looking around for some kind of adjustable resistor so i dont need to use too many switches but havent had any luck... i dont even know if they exist.

oh by the way i have a 2000 prelude and the po2s is factory and the so2s is DENSO #234-4092. i dont even kno if this is the right place to ask this question but any help is appreciated ifanyone feels like thinking so thx

 

I wouldn't try it on an obd2.........get a guinea pig car and test it out.

I'm kinda having a hard time figuring out what exactly you're trying to do.

You want to make an a/f control panel?....meaning you want to control your own a/f ratios by manipulating the sensor from the o2?

I think .40v on the signal wire of the o2 will give a reading of ~14.994 to the ecu

.45 - ~14.7
.50 - ~14.406

Something in that category.
*Information taken from SManager*

SO, here's what you do. Get your Ammeter out, see what kind of amperage is being used.
And use this formula - V/A = R
Volts / Amps = Resistance(ohms)

So, since the amperage will be constant. You will have to disable the O2 sensor some how. And induce some kind of low voltage to the signal wire going to the ecu. That voltage wire needs to be ran through a variable resistor - kinda like a light switch that dimms. Turn the "****" and it should change the voltage. I suggest you somehow replace your stock o2 sensor with a wideband so you can see what actual a/f ratio you're putting in. I really doubt you would be able to keep the o2 sensor because it will always induce different voltage at different times. IMO, i think this is a stupid idea. Just get some kind of wideband and hondata and you should be set.

Oh, and don't engrave anything i just said. See if it makes sense. Oh, get a test car first. Like a 91 crx or something

 

I think you would do better messing with the tps voltage. I believe thats one of the things that vafc changes. I think th way that the O2 swings it would be hard to control unless you had a wideband like mentioned above.

Honestly I would just buy a vafc or hondata ect.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nuezdaman44 &raquo;</TD></TR><TR><TD CLASS="quote">also if anyone has any suggestions on how to wire it i would appreciate it. im looking around for some kind of adjustable resistor so i dont need to use too many switches but havent had any luck... i dont even know if they exist.
</TD></TR></TABLE>

I would say you are looking for a potentiometer.

 

i know it doesnt sound all that realistic but im just doing it for fun.

im thinking the oscillating voltages given from the sensor wont make too much of a difference. it seems like a resistor would make higher highs and higher lows, and the ecu would trim fuel accordingly. if you think about it the ecu is basically just controlling the fuel using an average on narrowband sensors.

are potentiometers those little metal pole looking things? how do u use one?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nuezdaman44 &raquo;</TD></TR><TR><TD CLASS="quote">i know it doesnt sound all that realistic but im just doing it for fun.

im thinking the oscillating voltages given from the sensor wont make too much of a difference. it seems like a resistor would make higher highs and higher lows, and the ecu would trim fuel accordingly. if you think about it the ecu is basically just controlling the fuel using an average on narrowband sensors.

are potentiometers those little metal pole looking things? how do u use one?</TD></TR></TABLE>


Yeah it makes a hell of a difference. Why? Because if the voltage is always changing - how can u make sure you're getting the voltage needed?

I guess it wouldn't be THAT big of a deal if the voltages weren't so small.

Take a look at these -
.45 - ~14.7
.50 - ~14.406

So, how to you expect to control voltages to the hundreth degree?
Your best bet would be to get hondata - and tune the engine the way you want it. Disable the closed loop operation, and you should be set. Thats what I'm doing right now.

 

yea i plan on converting back to obdI with a new ecu and tuning it.. im just doing this for fun and to see if it actually works

i measured the current today and it seems to be at around 55-60 milliamps... so were looking at a .1v increase with 1.33 ohms of resistance. pretty small but not impossible.

what i cant figure out tho is if more resistance will increase the voltage or decrease the current so if anyone has some knowledge on this i could use the help

 

how will you know if it works? after your lump stops running?

 

Having an understanding of how the primary O2 sensor is involved in closed loop fueling, I can assure you that what you are trying is not going to work.

 

im gonna know if it works by the voltage readings given by a diagnostic tester jackass...

and shark, since u kno so much about it, tell me why it wont work... thats kinda what im looking for here... a reason not to do it

 

bumpage...

come on someone has to know the answer to this question... dont hold out on me

 

I'll bump you if you promise to post ownage pics when it locks up.

 

shark you're the man.
OP, search, start with the FAQs up top -&gt; VAFC and Preludes -&gt; let's settle the O2 sensor argument

when you verify where the FAQs are at, click here: https://honda-tech.com/zerothread?id=441935
don't click until you look at the FAQs

 

I am not sure what the main purpose of this is, but i know what you are theorizing on doing. But what is the purpose (not being a jackass)? 14.7:1AF is just fine for driving around town, if you WOT, it will ignore the signal coming from the O2 sensor anyways. So why play with the O2 sensors voltage.

 

am i correct that it wont ignore the ltft?

 

oh and like i said im just doing it for fun to see if its actualy possible... and qveon im glad u found my thread cuz i think i remember reading one of ur posts on here and it sounded like u know a lot about electricity

do u have any idea if im right that resistance wont affect the current? i mean it seems like if there was somewhere else for the current to go than it might but theres only gonna be one closed circuit back to the ecu... unless it just gets diverted to somewhere else in the system... my prblem is im having a hard time drwaing the cicuit im dealing with here

 

HOLY ****** **** IT WORKS

with three different switch positions i changed the avg from the 2nd sensor from 533 to 571 to 760 mV

i still need to wire it perfectly how i want it and put it on the front sensor (i tested it on the rear) but it actually works... i have files from autotap if u all still dont believe me