2G AEM Wideband wiring

[acemas99]

Quick question. I am installing an AEM UEGO gauge. I noticed that the AEM gauge has no wiring harness or connections for the stock O2 sensor wires.

My question is, what role does the rear O2 sensor play in stock ecu tuning. Does it play a role in fuel tuning, or is it only for a 02 check after the cat.

By the way, my cat is removed.

Anyhow, if the rear O2 IS involved in stock fuel tuning, I would like to mount the AEM in a new location (in between the stock front and rear O2 sensors). If the rear 02 IS NOT invovled in tuning, I would just replace it with the AEM gauge sensor.

Thanks

 

[1992awdlaser]

The rear o2 is just to make sure the catalytic converter is doing its job. It has nothing to do with the tuning. It will turn on the cel if you remove it though.

 

[95talon07]

WHAT!!! no no no dont remove the rear one and replace it with the new o2 sensor. the sensor after cat is for long term fuel trim. Your car will run lean as heck, so yes it does have something to do with the origanal tune of your car.. weld a new bung 36 inches from turbo. aka on the downpipe. if u dont have a bung to weld in dont do anything yet. buy one.

 

[T is for TURBO]

WHAT!!! no no no dont remove the rear one and replace it with the new o2 sensor. the sensor after cat is for long term fuel trim. Your car will run lean as heck, so yes it does have something to do with the origanal tune of your car.. weld a new bung 36 inches from turbo. aka on the downpipe. if u dont have a bung to weld in dont do anything yet. buy one.

wrong. rear o2 is only there to make sure the cat is in check. It has nothing to do with the LTFT, and will not cause your car to run lean.

 

[acemas99]

Thanks for the quick replies

Hm.. very mixed results haha. Count is 2-1. About removing the rear O2 - will that throw the CEL? Also I am getting link within the next week. If it does throw the CEL, is this one of the DTC's that link allows you to disable?

Thanks again

 

[98DropTop]

I didnt remove the rear O2 when I got mine installed.... It says right in the instruction manual that came with it the proper length down the dp to put the new O2 sensor... Do that...

 

[1992awdlaser]

Thanks for the quick replies

Hm.. very mixed results haha. Count is 2-1. About removing the rear O2 - will that throw the CEL? Also I am getting link within the next week. If it does throw the CEL, is this one of the DTC's that link allows you to disable?

Thanks again

It will throw a cel. But you can turn it off with dsmlink at this screen. http://dsmlink.com/images/screenshots/dtcdialog2g.gif


It's more like thousands-1. Just about everybody on dsmlink forums with a 2g has their wideband in the rear o2 sensor location. I am 100% positive it has nothing to do with the tuning. The other guy in this thread was just misinformed or something. If you want more people to back up what I am saying tell me. I will get one of the smartest people on this site to chime in.

If there is a cat on the car the wideband needs to be before it. If it is after the cat the cat will throw off the readings.

 

[acemas99]

I think you have satisfied me about the tuning. Of course more voices are always reassuring.

Anyhow, have you or any of the others running the aem rear setup noticed any measurement lags due to the sensor being further back on the exhaust system?

(The reading that you are seeing is delayed with respect to the instantaneous air/fuel ratio)

 

[1992awdlaser]

You won't notice it really. The only thing with it being back there is there is a greater chance of it being off due to an exhaust leak before the sensor. But if you make checking for exhaust leaks part of your routine you won't have a problem.

I will see if Steve wants to add his .02 cents about whether the rear o2 has anything to do with tuning. I (and I'm sure many others) consider him to be one of the smartest people on here.

 

[lazyazzdaddy]

Just a quick point I have to add. when you install a aem wide band like mine and hook it up to be logged in dsmlink they tell you to cut the rear o2 wire going into the ecu and tap the wide band into that..... so i would have to assume that there is no i'll effects to removing it. as long as you have dsmlink to clear the D.E.T.'s just my 2 cents and hey what do i know? most of the things i've learned came from here anyways.

 

[95talon07]

one more thing then. just to add. if i was informed worng thats one thing. and i am sorry for telling you what i have come to realize. But he didnt ask anything about using Link. what Makes u sure he even has link? And my last point is since he is running a stock ecu and he was asking about it WITH a stock ecu without Link, i am assuming, then he should do what the instructions say straight from AEM to weld in a bung 36 inches down form the turbo. thats all

 

[stefanOst]

one more thing then. just to add. if i was informed worng thats one thing. and i am sorry for telling you what i have come to realize. But he didnt ask anything about using Link. what Makes u sure he even has link? And my last point is since he is running a stock ecu and he was asking about it WITH a stock ecu without Link, i am assuming, then he should do what the instructions say straight from AEM to weld in a bung 36 inches down form the turbo. thats all

He said he's getting link within a week

 

[1992awdlaser]

Even wihout Dsmlink he could still use the rear o2 location for the wideband. It would just set off the check engine light. I don't know of a single car made that uses the rear o2(s) for anything other than checking the cat efficiency.

 

[lazyazzdaddy]

one more thing then. just to add. if i was informed worng thats one thing. and i am sorry for telling you what i have come to realize. But he didnt ask anything about using Link. what Makes u sure he even has link? And my last point is since he is running a stock ecu and he was asking about it WITH a stock ecu without Link, i am assuming, then he should do what the instructions say straight from AEM to weld in a bung 36 inches down form the turbo. thats all

All im saying is maybe you should read the whole thread befor you go rippin into people who leave usefull info.. im not trying to pick an arguement as i do agree that in the manule from aem it says to place the probe AT LEAST 36" away. as long as he has no cat and no exhaust leaks he will be fine useing the rear 02 bung.

 

[95talon07]

i wasnt ripping into anyone i was pretty much saying sorry if i was wrong.

 

[lazyazzdaddy]

i wasnt ripping into anyone i was pretty much saying sorry if i was wrong.

Then I am sorry !

 

[lq1driver]

i have my uego in the rear o2 no negative effects go ahead and do it