Hi I got a question about the VPRO and AFK... I know the o2 sensors on the AFK replaces the stock o2 sensors but which wire do u splice to trick the ECU into thinking that the oem o2 sensors are still connected?

Here's a few pix of the oem o2 harness (6 wires):

 

Why does OEM o2's have 6 wires. What are the 2 extra for.

 

How should I know... that's why I'm asking u guys to figure which wire goes to what. This is from a 2005 g35 coupe.

All I really want to know is which wire is the o2 output so I can connect the HKS.

 

I still have my factory 02 sensors, I just added 2 bungs to my down pipes (R/L wideband feedback) I will be back in the shop on Tuesday, I will find out for you then if you haven't found the answer.

-George
GT Motorsports

 

Thanks George... let me know when u can

 

I wasnt really asking you. lol i posted for others.

 

So you are trying to splice the HKS 02s into the factory 02s so the HKS 02s send a signal back to the OE ecu?

+1 on what George said. You could always add extra bungs, and just leave them in.

 

If i understand him correctly, he is trying to keep the ECU happy by having a signal sent to the factory O2's so its not confused when the V Pro is driving the car, however i got confused because it shouldn't really matter. The HKS O2's do the work they need to do and the OEM O2's are none the wiser, they just continue to function as normal as if nothing has happened.. the only ones that are confused are the Rear O2's once you add test pipes..

or i could totally misunderstand what he is really asking

 

Look at this you bafoon. I just did this yesterday. Do the same

I got only one wideband now and gettin another one soon.

 

Why don't you leave the stock O2 sensors connected?

 

I'm a little confused.

I thought the AFK replaces the stock primary o2 sensors therefore, I took them out and replace them with the dual wideband sensors that connects to the AFK then into the VPRO. So bc I completely took out the stock o2 sensor... doesn't the VPRO now have to trick the ecu into thinking that the stock 02 sensor is still there by giving a false signal?

So basically u guys are telling me to leave the stock primary 02 sensors plugged in and make an extra bung next to the primary o2 sensors and then I don't have to splice anything so both the ecu and vpro are happy?

 

So where should I mount the bung? Aren't the readings more accurate closer to the primary 02 sensor but it seems like majority is taping near the rear o2 sensors?

 

If you don't have cats, it doesn't really matter. If you have cats, you want it pre-cat.

 

The harness for the AFK will have two yellow wires one of which is striped and two white wires one of which is striped. These two sets of wires are the dummy outputs from the AFK that you will wire back to the stock ECU to make it happy.

 

New bung...that's it. Leave the factory 02's in place. As Doug mentioned, you could, if youi wanted to, output a spoofed signal to the factory ECU to keep it happy, but this isn't required.

 

will this throw a CEL once in awhile?

 

only on the rear O2's... then you could try your luck at foulers or a GTM ECU Flash

 

Why not just use the simulated output from the AFK?

 

You could, but it is probably simpler to use the stock O2 sensors.

Roger and I eliminated my stock MAF sensor housing with my Greddy kit, and used the F-CON to simulate the stock MAF sensor readings to feed into the ECU, but it took time to play around with the settings to get it so it would not throw the CEL.

 

You would still throw the code if you use the stock O2 sensors. For what he wants the easiest thing to do is take the stock sensors out run the dummy outputs from the AFk to the stock ECU to make it happy and just put the new widebands for the AFK in the stock bungs. No need to pull the exhaust off and have a new bung welded in.

Yes you have to play with the settings but in the end it would be a much cleaner setup.