Logging AFR with AP v3 and AEM UEGO - How to wire it up.

[SurfGuruJeff]

When I asked Phatron if I could log my AFR with my AP v3, he sent me the link to a kit sold by Moore Performance, but it comes with a relay and extra wiring that you don't need and can't justify spending $85 on. Overkill for just trying to log AFR on your Cobb Accessport. All you need to do is tap your AEM UEGO's 5v output into the correct wire that the ECU would normally use to read off of the Rear O2 sensor (or TGV Left/TGV Right) and then configure the Custom Sensor Input in Accesstuner.

I considered going straight to the harness coming out of the ECU, but opted to go with where I had a little more room while the engine was out which was right at the top of the transmission where there is a connection between two plugs. You may find it easier to tap in at a different location, say, further down the line towards the bottom of the car, or the other direction closer to the firewall.



Plug for the Rear O2 sensor on top of transmission (you may also use TGV Left or TGV Right).


We want the wire that communicates voltage changes from the rear O2 sensor to the ECU, which is the solid white wire on the 2008+ STi (check your year)



Reconnect the plug. *kind of important, haha



I fed the wire through boot for the Right Hand engine harness, then silicone'd over the slit I made. The wire will come through behind the glovebox area.


My AEM UEGO gauge's 12v ACC source is tapped into the radio harness and grounded nearby. The 5v output wire for logging (also conveniently a solid white wire) will connect to the yellow wire that we just routed behind the radio.


Make the necessary changes to your map for AEM UEGO scaling before monitoring. (helpful link from Cobb )


Log/monitor the parameter "Sensor Input Monitor Only (Rear O2)" or "Sens Only Rear O2" on your AP v3



*Note - you can also use TGV Left or TGV Right for monitoring and logging. Just depends on what you want to tap into, and what might make for the easiest access.

**Note - Just another note to anyone installing a AEM X-Series Wideband UEGO with the Bosch LSU 4.9 sensor, you also need to ground the BROWN wire for analog sensor ground. Otherwise it wont output 0-5v to the ecu.

[hondaeater69]

7.35 for a low AFR? holy cow

[SurfGuruJeff]

Originally Posted by hondaeater69

7.35 for a low AFR? holy cow

Hahaha. Yeah. Borrowed pic from Moore Performance.

[chchchino]

Just did this recently also. Did mine plug and play with a o2 sensor plug like this one:

http://www.bmotorsports.com/shop/pro...oducts_id/3242

and if anyone wants to buy just a pig tail, i believe you can get one pre wired from moto-east. worth it to note this will only work with a protuner. Im pretty sure ATR does not have custom sensor logging enabled.

[amac64]

hey bro could you explain how you used the plug that you bought?

thanks

[SurfGuruJeff]

Originally Posted by amac64

hey bro could you explain how you used the plug that you bought?

thanks

I didn't buy a plug. Go back and read thoroughly.

[TheTooTall]

Originally Posted by chchchino

worth it to note this will only work with a protuner. Im pretty sure ATR does not have custom sensor logging enabled.

So I know I'm late to this party but can anyone confirm that you have to have protuner in order to log custom sensors?

[slow.wagon]

Originally Posted by TheTooTall

So I know I'm late to this party but can anyone confirm that you have to have protuner in order to log custom sensors?

No, you only need the updated version of ATR. I don't remember the exact version, I think it was introduced after they started forcing people to take the class. I don't run the new version of ATR so I just tap into the TGV harness and do the conversion in excel, works perfectly fine and will work with all versions of ATR.

[JSR84]

I could be misunderstanding what you're saying so forgive me but... If you want to log/view custom sensor inputs you need to supply ATR with the voltage over data point information for that particular sensor so it can be converted into usable information. For that, you would need access to ATR or a Pro Tuner to do so.

[slow.wagon]

Originally Posted by JSR84

I could be misunderstanding what you're saying so forgive me but... If you want to log/view custom sensor inputs you need to supply ATR with the voltage over data point information for that particular sensor so it can be converted into usable information. For that, you would need access to ATR or a Pro Tuner to do so.

No need for an apology. I probably didn't read something and responded to hastily. To "log" AFR there are a few options and scenarios.

1. Get the latest version of ATR, wire up the AFR serial output with a DB9 and the appropriate USB converter if you don't have a serial port on your PC. To log with this method, you will both the AccessPort and the UEGO plugged into different USB ports simultaneously. This is the suboptimal option since it requires a lot of clumsy wiring, you will have sync issues with aligning the UEGO output with the AccessPort.


2. Use the latest version of ATR, wire up the AFR output to either the Rear O2 Sensor or TGV. The custom sensor option in ATR allows you to log this data natively and it is automatically converted and displayed in the right units. This is probably the most ideal path but it wont work for folks that run an ATR version that was released before 2016.

3. The last and most universal option (for folks with deleted TGVs). Wire the UEGO into the TGV (its just one wire). Log like usual but include the appropriate TGV voltage (left or right). When you log like this, all you need to do is convert the AEM voltage to AFR using a simple linear equation. I believe it amounts to: 2 x TGV Volts + 10. I arrived at this using AEM's scaling data provided in their documentation. I haven't had a problem with this approach.

Option 3 doesn't require ATR directly. You can do the conversion in excel but if you plan to use the data to change the map, you'll obviously need ATR.

[joek92]

So connect white aem 0-5v to o2 sensor side of pigtail.
What about the blue serial output aem wire, not needed?

Most importantly, can you hook up egt, oil temp, diff temp, and oil pressure in a similar way?

[SurfGuruJeff]

Originally Posted by joek92

So connect white aem 0-5v to o2 sensor side of pigtail.
What about the blue serial output aem wire, not needed?

Most importantly, can you hook up egt, oil temp, diff temp, and oil pressure in a similar way?

Correct, the blue serial wire is not needed.

Yes, you should be able to wire up similar sensors, then configure in AccessTuner

[point78]

Originally Posted by joek92

Most importantly, can you hook up egt, oil temp, diff temp, and oil pressure in a similar way?

How about Onboard realtime map switching?


http://forums.nasioc.com/forums/show....php?t=2776027

[Nurp]

Originally Posted by point78

How about Onboard realtime map switching?


http://forums.nasioc.com/forums/show....php?t=2776027

This is what I plan on doing with my WMI. nice.

[point78]

Originally Posted by Nurp

This is what I plan on doing with my WMI. nice.

It works fantastic.

I was testing it all out-in boost on the meth maps, trigger the fail safe, it's instant switch over to my pump maps-looking at data logs the boost drops right down from my meth level to pump level & it's really smooth.

No need to let off the throttle, just keep on keeping on.

The thing that has me most excited is now having two timing/boost maps.

This is huge-finally I can run nitrous without a stand alone ecu.

That's what's prevented me on this car. I'm just waiting on a built block to put it all together. Had it all on my last turbo car & I miss it dearly, it's a great void in my life.

Soon, soon...

[Nurp]

Originally Posted by point78

It works fantastic.

I was testing it all out-in boost on the meth maps, trigger the fail safe, it's instant switch over to my pump maps-looking at data logs the boost drops right down from my meth level to pump level & it's really smooth.

No need to let off the throttle, just keep on keeping on.

The thing that has me most excited is now having two timing/boost maps.

This is huge-finally I can run nitrous without a stand alone ecu.

That's what's prevented me on this car. I'm just waiting on a built block to put it all together. Had it all on my last turbo car & I miss it dearly, it's a great void in my life.

Soon, soon...

sick. I guess you just used the same wiring as the flex fuel install but with the meth signals instead?

[joek92]

Seems like this could be used for the torque app too unless I'm missing something.

[02nismokiller]

So this only works for 08+? I have an 05 sti

[SurfGuruJeff]

Originally Posted by 02nismokiller

So this only works for 08+? I have an 05 sti

Should work for most years, but you'll have to find the correct color wire (it is different) for your '05 to tap into.

[KeithS05RS2.5]

^^Curious too 02 WRX

[KeithS05RS2.5]

Looked today. Plug and wires are same for 02 WRX.

Wish these features were available in ATR. But I may hook up a redundant pigtail so I can keep it hooked up to the OEM harness for now and easily switch to the second pigtail with the UEGO input next time I do more with my e-tuner.

[chchchino]

I believe the new ATR does have custom sensor logging enabled.

[KeithS05RS2.5]

Hmmm, checked my ATR for updates and found none. Is this a new version thats needs a separate download?

[chchchino]

yes the newest version that requires a class.

[KeithS05RS2.5]

Ah I guess that'd be why. Thanks.