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Fitting Aem Afr gauge


shaz2010

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I've just got my Aem Afr wideband kit, I'm ok with wiring it up and fitting the gauge to the dash ect! The thing is I have a double decat and my O2 sensor is in the boss. Do I need to leave that in and then weld the bung that came with the kit next to it? Or can I take the O2 sensor out and put the new widband sensor in its place.

 

Cheers

 

And it's a uk spec so it's not a exhaust temp sensor like the jap spec.

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Its easier but he said that he only has a single lambda boss, so would have to weld in another, so I suggested the less work option.

 

Basically most wide-band kits have an output wire from the gauge/control unit that when set up can output a signal that is taken from the wide-band sensor, but is output in narrow-band form IE 0-1V just like the std sensor so allowing you to remove the std sensor fit the wide-band sensor and use the output wire to feed to the ECU in place of the std sensor, does that make more sense?

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Yes Ricky that's the answer I was hoping for :) so I would remove the std O2 sensor put the wideband in its place then run the aem wiring set as normal . That would leave me with the unplugged std O2 harness plug which is located under the seat.

Then would I run a feed from the back of the aem gauge to the std O2 harness plug or straight to the ecu to trick it to read the new wideband O2 sensor

 

Cheers mate

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I've heard lots of stories that the Standard O2 sensors are far superior compared to a gauge that changes 0-5v into 0-1v. The standard O2 will react a lot quicker and keep fueling the way it should when cruising etc but the output from the gauge has to be processed so might react a little slower meaning you might get hesitation, stumbling, worse fuel consumption. Just weld the other bung in further down and leave the standard O2.

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I've heard lots of stories that the Standard O2 sensors are far superior compared to a gauge that changes 0-5v into 0-1v. The standard O2 will react a lot quicker and keep fueling the way it should when cruising etc but the output from the gauge has to be processed so might react a little slower meaning you might get hesitation, stumbling, worse fuel consumption. Just weld the other bung in further down and leave the standard O2.

 

I think your listening to the wrong stories, why on earth would the std sensor be better than a wide-band sensor, these are used on most modern cars that run lean burn engines, the 0-5V signal is just compressed to a 0-1V, and will react just the same as the std sensor,

The speed of reaction of the sensor is not going to make any real difference as its the ECU reacting to the sensor output that takes the time, IE ECU sees the lean or rich voltage, as that's all the sensor does, and then adjusts the injector duty cycle to make the mixture either richer or leaner, that's it in a continues cycle until the ECU comes out of closed loop.

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I think your listening to the wrong stories, why on earth would the std sensor be better than a wide-band sensor, these are used on most modern cars that run lean burn engines, the 0-5V signal is just compressed to a 0-1V, and will react just the same as the std sensor,

The speed of reaction of the sensor is not going to make any real difference as its the ECU reacting to the sensor output that takes the time, IE ECU sees the lean or rich voltage, as that's all the sensor does, and then adjusts the injector duty cycle to make the mixture either richer or leaner, that's it in a continues cycle until the ECU comes out of closed loop.

 

Modern cars that run them are specifically designed for them.

 

It was from innovate themselves I read it about 5yrs ago when I was thinking of doing the same thing. But doubt it if you like lol

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From a thread where a guy is installing an aem one.

 

UPDATE

Some issues with running this setup have been brought to my attention:

- Having the WBo2 in the O2 housing will reduce its life

- The NB output of the UEGO to the ECU runs kind of funky because it doesn't cycle correctly.

- The UEGO should be grounded to the ECU. There have been some issues with properly grounding the UEGO. I chose to use the cigarette lighter ground if I have issues later I may change it to the O2 sensor ground instead.

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Well thats interesting because I have always used the Innovate wide-bands, and had no problems with running the narrow-band simulated output to the ECU, the fact that they have to mention grounding etc suggests to me that those who have had problems are not fitting and wiring things correctly.

If your going to run a WB properly and use the NB output then it should be supplied with power and earthed at the ECU to avoid any problems anyway.

How can running the sensor in the std position shorten its life? they are normally run in the manifold or in the turbo down pipe on cars that use them as std,

I have found that on a couple of cars you can get an inaccurate reading due to overheat, so a move or heat sink was needed,

I have run the sensor in the elbow of my single turbo Supra with no problems, and used the simulated output to feed the ECU.

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Yes I have also read the recommendations from Innovate, and like I said some cars do have poblems with sensor overheat, however I do wonder just what its down to, sensor or circuitry, as the very same sensors IE Bosch LSU 4.2 and 4.9 are fitted to a lot of cars as std, for instance the Golf R32 and a lot of other VAG turbo cars and lots of N/A cars, yet they are fitted to the turbo down pipe or manifold collector as std and encounter no problems.

 

In any case the OP asked if he could place the sensor in the std position and feed a NB output to the ECU, and the answer is yes, should it turn out that this location is not suitable for the AEM WB setup due to overheat, he can always have a boss welded into the decat pipe, but as he is looking to avoid this for now, so for the little work involved in this application its worth a try before just dismissing it IMO.

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Cheers for the info lads I've found this on the supraforums I think post #4 explains what am wanting to do!? www.supraforums.com/forum/showthread.php?499911-Aem-air-fuel-ratio-gauge-install

So it seems I need to run the white wire from the gauge to the ecu pin47b or 48b depending which one is the back O2 sensor which I think it would be 48b! That's based on a guess as 47first O2 sensor and 48second sensor ?!

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looks like pin 48 B (E9) ECU pinouts here,http://www.mkivsupra.net/vbb/showthread.php?35919-ECU-Pinouts&highlight=spec+ECU+pinout

 

You will also need to earth the unit to the ECU earth point, I also powered up the WB unit to my ECU but I would first check that its not going to draw too much current when the sensor is heating, don't forget to add a fuse as well.

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looks like pin 48 B (E9) ECU pinouts here,http://www.mkivsupra.net/vbb/showthread.php?35919-ECU-Pinouts&highlight=spec+ECU+pinout

 

You will also need to earth the unit to the ECU earth point, I also powered up the WB unit to my ECU but I would first check that its not going to draw too much current when the sensor is heating, don't forget to add a fuse as well.

 

Ta Ricky been a real help mate! I'm booked in at a exhaust place tomorrow to see if they could weld the bung in with having to remove the exhaust brackets and the decats themselves. If it all has to come off I will be hooking it up this way (in the exciting O2 sensor hole) myself. So all the info has been a good bit of help :)

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So I fitted this together today and just took it out for a test the readings are,

On cold start (can't remember) will update tomorrow !

Once warm and idle 14.9 (dead)

Driving around no boost (normal) is 14.6 - 15.2

On full boost (1bar at the moment uk decatted) is 11-11.9

Then off the throttle (after full boost) its goes to high point then to --

Does this sound ok ?

 

Cheers shaz

Edited by shaz2010 (see edit history)
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So I fitted this together today and just took it out for a test the readings are,

On cold start (can't remember) will update tomorrow !

Once warm and idle 14.9 (dead)

Driving around no boost (normal) is 14.6 - 15.2

On full boost (1bar at the moment uk decatted) is 11-11.9

Then off the throttle (after full boost) its goes to high point then to --

Does this sound ok ?

 

Cheers shaz

 

Sounds OK apart from I would like to be seeing around 11.2 - 11.4 max on full boost for safety 11.9 is a little too lean at 1bar, I would expect to see around 10.2 on a std ECU at WOT.

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