Wideband AFR issues?

[JMiller]

Ok, i have my wideband in the front O2 location and a plug in the rear. When i have the white wire sending the ecu an O2 sig from my wideband it runs stoich for about 20-30 sec then goes full lean but the exhaust smells like its dumping fuel in? heres a video with the ecu getting wideband output signal, and also taking of from a stop in full lean like that is hell.

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I have driven the car like that and only in the low rpms is it full lean cruising around 3k and up is 14.2-15.1ish. Now when i disconnect the wideband output signal from the ECU meaning no O2 signal for the ECU at all it runs 14.8 for about 30 seconds then starts to go rich and richer and richer until its at 11.2 and it stays in the 11.2-12.3 range unless im in boost then it goes even 10.0 and creeps up to 11.3 and sits there until i let off. Here is the video of what it does with no O2 signal to the ecu. Also it seems to run smoother as it richens up also the rpms increase.

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It drives fine with no O2 signal but it also tears through a tank of gas in no time also, if anyone knows what might be causing this issue i would greatly appreciate it. The only thing im thinking so far is the coolant temp sensor might be out of spec but my DMM was stolen awhile back along with my AFC neo and other things.

 

[Dsm4lyfe12]

Change the o2 sensor.

 

[JMiller]

Change the o2 sensor.

Is there a specific reason why you think changing the o2 sensor will fix my issue or is that just a wild guess?

 

[JMiller]

Wait a minute i just found a post by you gofer stating that the white wire goes to the ecu.
here is the post
http://www.dsmtuners.com/forums/articles-electrical-wiring/383190-1g-2g-aem-uego-wiring.html

Here's another one saying the white wire, and things like "it works", not mine.
http://www.dsmtuners.com/forums/turbo-system-tech/371916-narrowband-simulation-aem-uego.html

 

[gofer]

Instead of switching the wires change the rotary switch settings on the back of the gauge to P04. That should allow you to simulate the 0-1v signal across the white wire. AEM UEGO manual

 

[JMiller]

It's on P4 in the video watch when I start the car before the gauge starts reading it shows you what mode it's in and it's P04 where I set it.

 

[gofer]

Then it's either...

a) Not wired into the front o2 wire (76) at the ECU.
b) You didn't cut the front o2 wire first, you just tapped into it.
​

 

[JMiller]

I cut the wire from pin 76 and connected the white wire on p04 0-1v range to it leaving the original pin 76 wire dangling there. I will re check it though, I hope it's something simple like that.

 

[gofer]

Sorry I was being so blunt and to the point in my above posts, I was trying to help you from my iPhone thats 3 years old and has a hard enough time trying to type texts.

Both the rear o2 and front o2 wires are white and they are right next to each other at the ECU, its very easy to confuse them... ask me how I know. I'm 99% sure its not the sensor its either wiring, or for whatever reason, the gauge isn't outputting 0-1v across that wire even though its in the correct mode.

If you can verify that the gauge is wired into pin 76 (take a picture if you must) correctly try checking for the 0-1v coming across that white wire with a multimeter. It should show it fluctuating from 0.2v to 0.8v while the cars idling...

You did connect it to the ECU side of the cut wire, not the harness side... right? I'm going to delete my 1st post since the information is completely wrong, that way people don't pop in here and wire up the wrong thing.

 

[JMiller]

OK, will try the other white wire and cross my fingers.
Update: confirmed it was in the correct spot, pin 76 will still try the spot just to see what happens. Also still no dmm so I can't check the volts coming off the wire

Ok i tried connecting it to pin 75 and it did the same thing it does with nothing connected. Will look for a small flat head to try and mess with the rotary knob again.

 

[JMiller]

GOFER, question. Could a faulty/bad coolant temp sensor cause this, because i did have the wideband working with the ecu for about a week then my radiator separated(stock plastic end tanks) and and a few things stopped working correctly one thing being the cooling fans. Also still trying to find my other dmm.

 

[gofer]

A few things can lock the ECU into open loop, a faulty CTS can definitely do it. You can test it with a DMM too.

The good news is that you confirmed it wasn't the wiring...

 

[banishedmunk]

1 quick question why are you connecting the 0-1v wire up at all? when dsmlink will simulate off of the 0-5v input. DSMlink will take your 5v input and convert it into a signal the ecu can use as a 0-1v narrowband signal all you must do is use the NBO2 function in dsmlink

edit: just realized your not using dsmlink

 

[JMiller]

Yeah, no link yet. Thanks anyway though can use that info whenever i do get dsm link.

 

[JMiller]

I just came up with an idea on how to see what my wideband is sending out. My turbo timer has a hook up to show you narrow band readings so if i connect my widebands white wire to that then i can watch what it does while everything is connected. Wish me luck

 

[DSMTyson]

Lock it in open loop until you get the o2 sensor. My car did the same thing and is currently running in open loop. I like it better anyway.

_______________________________________________
Edit: woops, just noticed you dont have ECMLink.

 

[JMiller]

Lock it in open loop

I am, by not sending the ecu any air fuel readings. If i still had my afc neo i wouldn't of cared about running it the way i do cause i could lean it out at idle and cruise, etc.

 

[gofer]

Haha. Its forcing itself in open loop! Find anything out about the TT idea you had, I don't know if it would work or not but its worth a shot.

 

[JMiller]

OK, the results of my tests are as follows-
With the widebands output wire connected to the Turbo timers O2 input wire at idle the wideband gauge shows 12.3:1 and the TT shows 10.0:1 and wont go any leaner until the wideband gets up to 13.4:1 then the TT starts to show 11:1. Here is a chart of the numbers side by side

WB reading / TT reading

12:1 / 10:1

13.5:1 / 11:1

14:1 / 12:1

15:1 / 13:1

16:1 / 13:1

17:1 / 14.6:1

--:-- / 14.7:1

I'm pretty sure this is exactly what the ecu sees when i have the wideband connected to it which would explain why it wants to stay full lean all the time, the ecu thinks its at 14.7 when its really at 17:1. Now i ask WTF, is the gauges output sending unit messed up or what. My information is leading me to believe i need a new wideband or an AFC.

 

[AlaskanDsm]

It's only a SIMULATION MUHHAHAHAHA...


Sucks but the other side its that possible the TT doesn't have the same reading cababilities that the AF gauge does (meaning it would be good to verify with a third source to confirm the correct numbers). Too bad you weren't closer or I'd lend you my gauge just to see the outcome of swapping gauges would be. Maybe see if someone is willing to lend you their gauge just for testing purposes.

 

[dsmrollerz90]

Mine at idle is at about 17.9, and at WOT its about 14.0-13.7. Is this good or bad? look at my mods list to see if there is anything I am doing wrong.

 

[JMiller]

Mine at idle is at about 17.9, and at WOT its about 14.0-13.7. Is this good or bad? look at my mods list to see if there is anything I am doing wrong.

Just looked at your mods and no it should not look like that it should idle at 14.7:1 cruise at 15ish:1 and WOT should be close to 11:1.

? do you have the honeycombs in that evo MAF

It's only a SIMULATION MUHHAHAHAHA...


Sucks but the other side its that possible the TT doesn't have the same reading capabilities that the AF gauge does (meaning it would be good to verify with a third source to confirm the correct numbers). Too bad you weren't closer or I'd lend you my gauge just to see the outcome of swapping gauges would be. Maybe see if someone is willing to lend you their gauge just for testing purposes.

Yeah, most of the car people i know are about 2 hours away with the exception of a few and they use the LC1 wideband, and my third source is gonna be my DMM voltage reading as son as i can find it.

 

[JMiller]

Went back out today to mess with the car and realized during the first 30 seconds of starting the car the wideband and turbo timer are almost exactly the same. It's like once the sensor warms up the output voltage screws up.

 

[gofer]

Honestly, I don't think its the sensor but you can replace it and see what happens but if it were me I'd find that DMM and check the actual voltage.

If you want to replace it you can save shipping costs and AEM "brand" costs by just going to Auto Zone and picking a Bosch o2 sensor up, it plugs right into the WB harness and its a 0-5v. Bosch LSU 4.2 17018

 

[JMiller]

Still no DMM results yet(might just buy a new one), but according to the TT the voltage range is betwwen .30v and 1.16v with .30 being 14.7:1 of TT and 17:1 on WB.
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