How do you hook up A/F Gauge??? [Archive] - Club RSX Message Board

: How do you hook up A/F Gauge???


OakleyMan
04-06-2006, 12:59 AM
I have an autometer ultra-lite A/F gauge, what wire on the oxygen sensor do you hook up the purple wire from the A/F gauge to :confused: There are two black, one white and one green between the oxygen sensor and the harness. Or do I hook it up somewhere else???

CRIBBIE
04-06-2006, 06:13 AM
yeah there is 2 ways to do it, ill look it up at work, iv got it done to mine bit its been such a long time and i dont remeber. ill repost shortly...

OakleyMan
04-06-2006, 01:02 PM
Cool, much appreciated :thumbsup:

gotBOOST
04-06-2006, 02:17 PM
you hook it up to your ECU

bcolenj
04-06-2006, 03:12 PM
Dont touch any of the wires on the primary o2 sensor of an rsx. This is a semi wide-band o2 sensor and will not work with any autometer guages. The o2 sensor after the cat is narrowband and the type of sensor that the normal air/fuel guages are made for. Putting a guage on a sensor after your catalytic converter is in fact almost pointless. If you have a race header, you can do this because you have no cat. This would give you an air/fuel gauge that works to the effect of 90% of the a/f guages installed on other cars. This basically means your guage is just a fancy and expensive light show. The guages dont tell you your air/fuel ratio they just sweep back and forth, illuminating the leds. If you really want an A/F guage. PLX and AEM both make guages that have their own wideband or semi-wideband sensor that allows them to operate as a real guage and are usually accurate to .1 A/F. These guages are not cheap and they require you to either weld an additional o2 bung into your header. If you have a DCRH and KPro you can turn off obd2 and remove the secondary o2 sensor and put the Wideband from the aem or plx guage in there. If you have a Toda header, I believe it comes with 3 bungs but im not positive. For other headers your on your own.

bcolenj
04-06-2006, 03:14 PM
Someone should also make a Air/Fuel gauge sticky because it seems to be commonly asked about.

OakleyMan
04-06-2006, 03:30 PM
you hook it up to your ECU

Ok so which wires do you hook it up too, I still dont know which wires to tap into :confused: It seems like everyone has one of these in there cars so what wires is everyone hooking them up too :dontknow:

CRIBBIE
04-06-2006, 03:48 PM
im goin out to look now, and by the way, i think mine is hooked up to the secondary and it does not flash back and forth while driving, when i had my test pipe in the light dances constantly no matter how i drive it. sowith the cat in it was able to give or show better readings

CRIBBIE
04-06-2006, 03:56 PM
ok read this carefully, hook it to the:

ECU
Left wire harness (closest to the centre of the veh)
Second row down (middle row)
White/pink wire (White solid with pink line)

CRIBBIE
04-06-2006, 03:57 PM
its the second wire over from the left, i just ran out and took a look for ya bud

bcolenj
04-06-2006, 04:01 PM
im goin out to look now, and by the way, i think mine is hooked up to the secondary and it does not flash back and forth while driving, when i had my test pipe in the light dances constantly no matter how i drive it. sowith the cat in it was able to give or show better readings

Please learn about what the cat does and how an A/F guage works. Putting the guage on after the cat will in no way give a "better" reading. The light may not dance because after the exhaust goes through the catalyst your a/f ratio will not be what it was when it came out of the engine. This in turn defeats all tuning purposes whatsoever and completely negates the purpose of even having an air fuel guage.

CRIBBIE
04-06-2006, 04:15 PM
we all know having a air fuel gauge is just for looks, most of the time, its not like you can even do anything about the readings it give you unless you have got k-pro, i only have it to so show me the fuel mix characteristics in certain driving conditions, im runny stock ESU so there is oviously no tuning that can be done..... i know quiet a bit about cats a matter of fact. im a damn mechanic...

CRIBBIE
04-06-2006, 05:17 PM
its not like you can take your car for a ride and watch the gauge and say ah shit, im running to lean, and go lift up the hood and turn the mixture screws out a quarter of a turn......

bcolenj
04-06-2006, 05:48 PM
No but with a properly functioning A/F guage you can tell if your car does need to be tuned. With a A/F guage connected to a narrowband sensor that only sweeps/dances, your just wasting money and if you even try hooking that guage up to your semi-wideband primary o2 sensor in the rsx, your also damaging your car in addition to getting a guage that doesnt work.

CRIBBIE
04-06-2006, 06:03 PM
i know what your getting at, the O2 sensors works on a reaction to the exhaust gasses, and it relays this to the ECU by sending back a particular voltage ( certain voltage sent back tells the ECU weather its lean or rich) and by adding another system with wires and connectors will increase the resistance witch would lower or give false readings from the O2. this voltage is very persice and is actually read in mili volts, addind a small 5 foot long wire into this system would alter the reading.
is that what you were getting at?

bcolenj
04-06-2006, 08:56 PM
i know what your getting at, the O2 sensors works on a reaction to the exhaust gasses, and it relays this to the ECU by sending back a particular voltage ( certain voltage sent back tells the ECU weather its lean or rich) and by adding another system with wires and connectors will increase the resistance witch would lower or give false readings from the O2. this voltage is very persice and is actually read in mili volts, addind a small 5 foot long wire into this system would alter the reading.
is that what you were getting at?

Technically the resistance would be lower but yes that is the general idea. The biggest problem comes in when you look at how the RSX o2 sensors are set up. The primary semi-wideband sensor is what our ECU uses to determine A/F ratio in open-loop. The output of the sensor I believe ranges from 0-5v and either fully or semi linearly correlates to A/F ratio. The secondary o2 sensor is only used by our ECU for monitoring of our catalytic system to ensure its in working order. The output of this sensor is 0-1v range and to my knowledge is NOT linear in correlation to the "narrow band" of A/F it can distinguish from. This I believe is part of the reason why these guages sweep or dance back and forth along with the fact that in most cars with only narrowband sensors, the ECU oscillates the A/F ratio with the average at stoich due to the limited processing power available in older ECUs.

Trying to hook a guage up to the primary is just a bad idea because the guage isnt meant for the 0-5v swing, and would always read fully lean or rich, whichever the 1v end of the narrowband sensor is. It also will lower the resistance between the primary o2 and the ECU causing the ECU to receive false information. Using the secondary sensor with an A/F guage will in no way impact the fuel delivery on an RSX although it may cause the ECU to throw catalyst errors due to the change in the secondary o2 sensor voltage and current received by the ECU. If you do this, the guage will just sweep/dance like it does on other cars.

My electrical knowledge far exceeds that of o2 sensors but this is what I believe to be accurate.

Someone who really knows about the exact operation of both wideband and narrowband sensors along with how the ECU handles the processing of them should really write up a sticky on A/F guages.

EDIT: I just found this http://www.hondata.com/techplx.html

CRIBBIE
04-06-2006, 09:12 PM
nicely done my friend. i did all of this resurch before i installed this gauge, i knew i had 2 options but i cant remember witch one i hooked it too, i want to say that i connected it to the secondary due to the fact it holds less responsablity in eng operation and fuel mixture...
im not trying to plug up this thread, and i apologize in advance. i can never seem to get a lagit answer out of this question, why would a RH lean out your fuel mixture? or is this not even true to begin with?

bcolenj
04-06-2006, 09:17 PM
The combination of both an Intake and a Race Header allow air to both flow in and out of your engine alot more freely. You're allowing more air in and giving it the same amount of fuel. That is what is causing the car to run lean. A K-Pro will solve all the problems of running lean in about 10 minutes of street tuning.

CRIBBIE
04-06-2006, 10:31 PM
"one hand washes another" with more air comes more fuel, right? and with the exhaust all its mearly doing is moving wasted (exhaust gesses) energy from one point to another (to the rear of your veh) im not saying what you said is wrong, im just not grasping the concept. and if indeed there is a lean mixture that ocurse when installing a CAI+RH wouldnt the primary O2 pick up this change and make the proper corrections?

OakleyMan
04-06-2006, 10:34 PM
I know this is a stupid question but where exactly is the ECU???

CRIBBIE
04-06-2006, 10:42 PM
ouch brother!! hahaha its below your glove box, passenger side right above the feet, theres a black piece of carpit with 3 round clips take them out and BAM!!!!! there it is....

OakleyMan
04-06-2006, 10:46 PM
Yea I know :o thanks for lookin out though :spin:

iwilson
04-07-2006, 02:01 AM
The output of the sensor I believe ranges from 0-5v and either fully or semi linearly correlates to A/F ratio.

For a normal wide-band sensor this is correct. But Honda in their infinite wisdom choose to use a semi-wide band O2 sensor that outputs a changing current not voltage - the ECU reads the current change not the voltage. The secondary is a standard voltage based narrow band sensor.

Keith DC5
04-07-2006, 07:22 AM
DO NOT TOUCH ANY OF THOSE WIRES! Before you read any further, I highly suggest that you ditch the A/F gauge for an EGT gauge instead. You'll understand why as you read on:

Before touching ANYTHING on your car, remove the negative cable from your battery.

The ECU location is behind the glovebox, under the blower motor for the cabin fans. If you look under the glovebox, you'll see 3 retaining clips holding up that carpetted panel. You need to remove it by pushing in on the center of those clips, and they should simply fall out. After removing that panel, look for connector E which is on the far left hand side of the ECU (driver's side). You need to tap into 1 to 3 wires depending on where you wire the ground and ignition.

Anyway, before I go any further please read the instructions CAREFULLY! If I say "white wire with a red stripe" that doesn't mean "red wire w/ a white stripe." Scrutinize it very carefully because the wires look very similar and it's easy to get confused.

The red wire on your A/F gauge is the ignition line. That taps into any 12v power source such as the cig lighter, etc. You can also crimp a connector on the end of it and plug it into your fusebox. There's also a few wires on the harness that provide power, but I do not recommend tapping into any of those.

The black wire is the ground wire so you can tap into the ECU grounds, or mount it to the chassis. If you tap into the ECU ground, please read the following very carefully: There is a pink wire in connector E that supplies the sensor grounds. It is the 4th from the last terminal on that connector, and it's located between a brown wire w/ a yellow stripe, and a yellow wire w/ a blue stripe. If you don't know which one is connector E, just sit in the passenger seat, and it's the one all the way to the left on the ECU.

The violet wire is the signal wire and what it taps into is VERY important. Once again, be sure you're looking at CONNECTOR E which is the plug that's closest to the driver-side. Now look for a white wire w/ a red stripe. It should be the 2nd to the last terminal in the connector. It should be between a green wire w/ a yellow stripe, and a brown wire with a yellow stripe. That white wire w/ the red stripe is the secondary O2 wire and can be used to determine A/F ratios.

Now please understand that this works optimally only if you don't have a cat converter. If you have a fully functional catalytic converter installed, the secondary O2 will see less fuel particles causing your A/F gauge to read LEAN. There is no way around this because there's no other sensor to tap into. If you tap into the primary, you'll mess up the A/F ratios since the gauge is drawing current away from the ECU. As a result, your car will think it's running leaner/richer than it really is since the A/F gauge is distorting the sensor's readings.

This is why I suggest you buy an EGT gauge instead of using your A/F gauge. The EGT has a remote-mounted probe that measures exhaust gas temps. The leaner you run, the hotter the gas. It's also a lot easier to install although it costs substantially more. With that said however, you don't need either of them so I'm not sure what you're hoping to accomplish with the A/F or EGT gauges.

CRIBBIE
04-07-2006, 05:09 PM
keith DC5
i vote that you should change your name to "THE BRAIN" sirously man your a walking, talking, shitting book of knowlage!!!!:thumbsup: :thumbsup:

ChanManDC5
11-07-2006, 06:44 PM
the white wire w/ red stripe is the same for a 05-06 type-s ECU right??


and i know it's pretty pointless to have an a/f gauge, but my friend gave it to me for free... so no money wasted here.. :thumbsup:

ekinwong
02-01-2007, 02:09 AM
i think the 05-06 ecu is different right?? because i checked the wire, i didn't see a wire which has brown with yellow strip.

Matrix86
06-08-2007, 12:17 PM
the white wire w/ red stripe is the same for a 05-06 type-s ECU right??


and i know it's pretty pointless to have an a/f gauge, but my friend gave it to me for free... so no money wasted here.. :thumbsup:

bump for answer.....


also what makes a a/f gauge pointless?

Matrix86
06-08-2007, 09:52 PM
ttt for answer... thanks-

03dc5james
06-08-2007, 11:23 PM
A/F guages are pointess without a wideband as stared above. If you're looking for an acurate reading on weather your running rich or lean, just get an EGT (exhaust gas temp) guage. Does the same thing and you wont have to spend a billion dollars.

Matrix86
06-09-2007, 03:14 AM
A/F guages are pointess without a wideband as stared above. If you're looking for an acurate reading on weather your running rich or lean, just get an EGT (exhaust gas temp) guage. Does the same thing and you wont have to spend a billion dollars.

but don't you have to cut your exhaust for an EGT?

Matrix86
06-10-2007, 12:32 AM
DO NOT TOUCH ANY OF THOSE WIRES! Before you read any further, I highly suggest that you ditch the A/F gauge for an EGT gauge instead. You'll understand why as you read on:

Before touching ANYTHING on your car, remove the negative cable from your battery.

The ECU location is behind the glovebox, under the blower motor for the cabin fans. If you look under the glovebox, you'll see 3 retaining clips holding up that carpetted panel. You need to remove it by pushing in on the center of those clips, and they should simply fall out. After removing that panel, look for connector E which is on the far left hand side of the ECU (driver's side). You need to tap into 1 to 3 wires depending on where you wire the ground and ignition.

Anyway, before I go any further please read the instructions CAREFULLY! If I say "white wire with a red stripe" that doesn't mean "red wire w/ a white stripe." Scrutinize it very carefully because the wires look very similar and it's easy to get confused.

The red wire on your A/F gauge is the ignition line. That taps into any 12v power source such as the cig lighter, etc. You can also crimp a connector on the end of it and plug it into your fusebox. There's also a few wires on the harness that provide power, but I do not recommend tapping into any of those.

The black wire is the ground wire so you can tap into the ECU grounds, or mount it to the chassis. If you tap into the ECU ground, please read the following very carefully: There is a pink wire in connector E that supplies the sensor grounds. It is the 4th from the last terminal on that connector, and it's located between a brown wire w/ a yellow stripe, and a yellow wire w/ a blue stripe. If you don't know which one is connector E, just sit in the passenger seat, and it's the one all the way to the left on the ECU.

The violet wire is the signal wire and what it taps into is VERY important. Once again, be sure you're looking at CONNECTOR E which is the plug that's closest to the driver-side. Now look for a white wire w/ a red stripe. It should be the 2nd to the last terminal in the connector. It should be between a green wire w/ a yellow stripe, and a brown wire with a yellow stripe. That white wire w/ the red stripe is the secondary O2 wire and can be used to determine A/F ratios.

Now please understand that this works optimally only if you don't have a cat converter. If you have a fully functional catalytic converter installed, the secondary O2 will see less fuel particles causing your A/F gauge to read LEAN. There is no way around this because there's no other sensor to tap into. If you tap into the primary, you'll mess up the A/F ratios since the gauge is drawing current away from the ECU. As a result, your car will think it's running leaner/richer than it really is since the A/F gauge is distorting the sensor's readings.

This is why I suggest you buy an EGT gauge instead of using your A/F gauge. The EGT has a remote-mounted probe that measures exhaust gas temps. The leaner you run, the hotter the gas. It's also a lot easier to install although it costs substantially more. With that said however, you don't need either of them so I'm not sure what you're hoping to accomplish with the A/F or EGT gauges.

is this the same way of doing things for a 06?

drumnatural
06-10-2007, 12:35 AM
You don't want an A/F gauge unless it's the AEM UEGO or get your A/F via the Brockway Engineering Monitor

Matrix86
06-10-2007, 12:41 AM
I know they aren't very accuate, but they have to work somewhat well... And are a lot cheaper then the uego. So that is why I got a A/f gauge.... I just don't know how to install it.

drumnatural
06-10-2007, 12:46 AM
I know they aren't very accuate, but they have to work somewhat well... And are a lot cheaper then the uego. So that is why I got a A/f gauge.... I just don't know how to install it.

Then you shouldn't have gotten it.

So now sell it.

You really don't want to splice into any wiring in regards to what dictates your a/f.
It's based off voltage which can easily be thrown off with the addition of extra wire.

Matrix86
06-10-2007, 12:55 AM
Then you shouldn't have gotten it.

So now sell it.

You really don't want to splice into any wiring in regards to what dictates your a/f.
It's based off voltage which can easily be thrown off with the addition of extra wire.

well if only I had the exta $250buxs to spend...Will you give me the extra money? :coffee:

I got the gauge cheap, I'm prob. not even going to keep it in the car for very long. Just long enough to see if I'm running too lean.

So if someone could tell me if its the same installation on an 06 as it is on an 02-04, that would be awesome. :chuck:

JayPee_inc
07-12-2007, 12:13 AM
so is the AEM Uego kit (http://www.clubrsx.com/cr/AEM-30-2301.html) worth it in the way of helping me tune my vafc2

and is it a stand alone system, so it doesnt interfere with the volts as others were saying earlier in the thread. also, will the sensor provided take the place of the secondary o2 sensor or can it do that? thanks for help in advance

Stitch
07-12-2007, 12:41 AM
Placing your wideband in the second o2 port isn't that great of an idea, since its furthest away from the combustion of the engine, the reading wont be that accurate, you want your wideband to be close enough for the most accurate reading, but not close enough to get burnt.

highintake87
09-26-2007, 11:06 PM
if i have kpro what wire do i connect my a/f to?

ocd
12-05-2007, 02:55 PM
The violet wire is the signal wire and what it taps into is VERY important. Once again, be sure you're looking at CONNECTOR E which is the plug that's closest to the driver-side. Now look for a white wire w/ a red stripe. It should be the 2nd to the last terminal in the connector. It should be between a green wire w/ a yellow stripe, and a brown wire with a yellow stripe. That white wire w/ the red stripe is the secondary O2 wire and can be used to determine A/F ratios.


It's very strange, on the 2002 RSX-s that I am working on, that white/red stripe wire has a range of apprx 1-4v. It never goes below 1v and the A/F gauge is always pegged on rich. This is confirmed on the K-Pro. SO2 fluctuates between 1.5ish v to 4.08v. The primary O2 seems to be the one that moves between 0 and 1v (on the K-Pro). Also, when I connect the purple wire from the A/F gauge to the white/red stripe wire, the value to the ecu changes (goes lower). I'm puzzled. These cheap A/F light shows only read up to 1v, so what's the solution in connecting these gauges?

I don't think there is a viable solution.

Axix23
12-05-2007, 11:37 PM
don't mess with an a/f gauge.. kpro will do all that..

marshallboi903
12-02-2009, 04:24 PM
this really helped me out

Keith DC5
12-02-2009, 11:59 PM
^ Hopefully it didn't.

I failed to add that this was merely the correct way to splice into the primary HO2S. I failed to mention that you should never tap into a wideband sensor. Read what I posted here:

http://forums.clubrsx.com/showthread.php?t=636276

is this the same way of doing things for a 06?

Just refer to a pin chart/diagram. The AFR gauge only needs a 12v source, a ground, and a signal wire. The power and ground you can receive from anywhere, but the signal wire needs to be spliced into the HO2S signal wire. As I've mentioned above however, you don't splice into a wideband sensor.

marshallboi903
12-03-2009, 12:53 AM
^ glad I'm starting my wiring n the morn. Thanks for the help.