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Discussion Starter #1
Hey guys.

I've put a single turbo on my 98' Aristo JZS161 (2JZ GTE VVTI OBD2). Currently painting the engine bay and Will be dropping it back in during the weekend. Now, I'm wondering on what I have to do with the connectors that went to all the twin turbo stuff like the VSVs so that it won't throw a CEL? What resistors do I need and where? Also I'll be running narrowband sim from the AEM UEGO. Am I right saying that I can leave the stock o2 unplugged, and just splice into the lambda signal wire with the AEM?
 

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handy with the steel
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I don't believe you need to put resistors in the VSVs. These are output devices, the ECU isn't looking for any feedback from them.

This is the first time I've heard of narrowband simulation, but the concept makes sense. The idea is that you'd use the wideband to generate a "dummy" narrowband signal for the factory ECU, correct?

If that's the case then yes, you'd just leave off the factory O2 sensor entirely, but I don't think you'd be able to simply wire the wideband signal into the factory narrowband input. The reason is that the voltage response is different.

Narrow band:

251139


Wideband:

251141



...You can see on these two example sensors the voltage for stoich is different for both of them.

Does the AEM wideband controller have a dedicated narrowband output that you can scale to match the factory narrowband response?
 

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Now...Whitesupra94
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Here you go:
<- the link is showing as MKIV.com, but it's the VSV specific article

FYI, even though MKIV.com is down, they have posted a web archive for the time being. I found that out via their MKIV.com facebook page

There's also an article in there about building an 02 sim.

I don't know how the AEM UEGO works...but I'd imagine you'd need to do the same type of O2 simulator wiring as described in the O2 sim article. Just a guess though
 

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Discussion Starter #4
I don't believe you need to put resistors in the VSVs. These are output devices, the ECU isn't looking for any feedback from them.

This is the first time I've heard of narrowband simulation, but the concept makes sense. The idea is that you'd use the wideband to generate a "dummy" narrowband signal for the factory ECU, correct?

If that's the case then yes, you'd just leave off the factory O2 sensor entirely, but I don't think you'd be able to simply wire the wideband signal into the factory narrowband input. The reason is that the voltage response is different.

Narrow band:

View attachment 251139

Wideband:

View attachment 251141


...You can see on these two example sensors the voltage for stoich is different for both of them.

Does the AEM wideband controller have a dedicated narrowband output that you can scale to match the factory narrowband response?
Yes, that's correct. The idea is that you use the wideband, in this case AEM UEGO, to get data from it's lambda sensor and "convert" it into narrowband 0-1v signal. It has a small screw on the back side you use to switch between different modes like normal 0-5v wideband and 0-1v narrowband. It has a wire you can use to splice into the ECU to feed the data. What I was wondering about more is the heater circuit for the o2 sensor. Won't the ECU throw a cel light if it doesn't detect it (aka removing / disconnecting the OEM o2 sensor)?
 

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Discussion Starter #5



  • Here you go:
    <- the link is showing as MKIV.com, but it's the VSV specific article

    FYI, even though MKIV.com is down, they have posted a web archive for the time being. I found that out via their MKIV.com facebook page

    There's also an article in there about building an 02 sim.

    I don't know how the AEM UEGO works...but I'd imagine you'd need to do the same type of O2 simulator wiring as described in the O2 sim article. Just a guess though
    Thanks alot man! Couldn't manage to find any info when searching. Didn't quite mean an o2 sim, but s narrowband sim. So you basically use a wideband gauge that has a function of "converting" 0-5v wideband signal into 0-1v narrowband signal which you can feed to the ECU on the OEM o2 input cable. Only problem I could think of is that the ECU might throw a CEL if I disconnect the o2 and it doesn't see a o2 heater signal. Any way around that?
 

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Now...Whitesupra94
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  • Thanks alot man! Couldn't manage to find any info when searching. Didn't quite mean an o2 sim, but s narrowband sim. So you basically use a wideband gauge that has a function of "converting" 0-5v wideband signal into 0-1v narrowband signal which you can feed to the ECU on the OEM o2 input cable. Only problem I could think of is that the ECU might throw a CEL if I disconnect the o2 and it doesn't see a o2 heater signal. Any way around that?
I think it's in that article, but maybe not. Basically what I've seen advised is leave the 02 sensor connected. Tape it up under the car or something like that just for the sake of the heater wire. I've still got mine mounted in the exhaust for that very reason, even though there's an 02 Sim connected to my Fields ECU harness.

Edit:
Yea here it is
"The original sensor should still be dangling around, or plugged into the downpipe. The reason is that ECU also monitors the resistance of heater circuit inside the sensor. If you want to COMPELTELY disconnect it, you will need to measure the resistance of the heater circuit and install the right resistor between ECU PIN #72 and ECU PIN #31 Anyway, there is no need to do it if you just leave O2 sensor alone and only intercept the oxygen signal wire."
 

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Discussion Starter #7
I think it's in that article, but maybe not. Basically what I've seen advised is leave the 02 sensor connected. Tape it up under the car or something like that just for the sake of the heater wire. I've still got mine mounted in the exhaust for that very reason, even though there's an 02 Sim connected to my Fields ECU harness.

Edit:
Yea here it is
"The original sensor should still be dangling around, or plugged into the downpipe. The reason is that ECU also monitors the resistance of heater circuit inside the sensor. If you want to COMPELTELY disconnect it, you will need to measure the resistance of the heater circuit and install the right resistor between ECU PIN #72 and ECU PIN #31 Anyway, there is no need to do it if you just leave O2 sensor alone and only intercept the oxygen signal wire."
Oh alright. Didn't see that. Thanks man!
 

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Tree Hugger
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251169


251170


I'm not using that top port close to the turbo, but I am using the two middle ports. One is the stock narrowband hooked up to the oem vvt-i ecu and the other is my aem uego wideband going to a gauge. I also didn't wire any resistors when doing the single turbo conversion.
 

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Discussion Starter #9
View attachment 251169

View attachment 251170

I'm not using that top port close to the turbo, but I am using the two middle ports. One is the stock narrowband hooked up to the oem vvt-i ecu and the other is my aem uego wideband going to a gauge. I also didn't wire any resistors when doing the single turbo conversion.
Nice setup. Have you ever tried the narrowband sim on the UEGO or just been using the stock o2 sensor? And you don't get a cel from running no resistors?
 

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No CEL from lack of resistors no, only from lack of speed sensor (I have an R154 swap and my electronic speed sensor went out, adapted to the marlin crawler setup which uses the jza70 cable and converts the signal, and it died after 6 months).

I also have not tried the narrowband sim on the uego, i only use it for my wideband gauge to monitor AFR myself, and my setup came with the stock front o2 sensor "pre-cat" which is the only one I use with no issues other than my boost being too low and pegging 10.0 AFR under WOT at 10psi which the stock computer doesn't really like. Started turning up the boost to 11-12 lbs and its pulling a lot better but still 10.2-10.0 AFR but I plan to boost leak before going up more.

I think the only modification I had to make on my chassis (jzs147 gs300) was jumping a resistor on the cluster to get my tach to read and wiring a neutral safety switch.

edit: Oh and OP if you're using stock computer/MAF make sure you recirculate your BOV after your mass air flow or it will stumble hard coming off boost. My setup isn't very clean but shows it pretty clearly.

251211
 

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Discussion Starter #11
No CEL from lack of resistors no, only from lack of speed sensor (I have an R154 swap and my electronic speed sensor went out, adapted to the marlin crawler setup which uses the jza70 cable and converts the signal, and it died after 6 months).

I also have not tried the narrowband sim on the uego, i only use it for my wideband gauge to monitor AFR myself, and my setup came with the stock front o2 sensor "pre-cat" which is the only one I use with no issues other than my boost being too low and pegging 10.0 AFR under WOT at 10psi which the stock computer doesn't really like. Started turning up the boost to 11-12 lbs and its pulling a lot better but still 10.2-10.0 AFR but I plan to boost leak before going up more.

I think the only modification I had to make on my chassis (jzs147 gs300) was jumping a resistor on the cluster to get my tach to read and wiring a neutral safety switch.

edit: Oh and OP if you're using stock computer/MAF make sure you recirculate your BOV after your mass air flow or it will stumble hard coming off boost. My setup isn't very clean but shows it pretty clearly.

View attachment 251211
Oh alright, good to hear :). Will try without the resistors then. And I think I'll try the UEGO narrowband sim first (makes it a bit easier to fab the downpipe), if that doesn't work out I'll go the route you went. And I know about the BOV. Gonna be running no BOV and the Maf on the cold side right before the TB. Heard that for some people it works great, while others say it's problematic. Most likely gonna convert to MAP using the DET3, so the maf will be needed just to create a base fuel map. Did you fab the OEM o2 flange yourself or does someone sell them, incase I need one.
 

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