Wideband in rear O2 location?

Anyone running their WB02 in the stock rear O2 location? I realize there will be a slight lag in response time but I am curious what everyone's experience has been running it there.

I am looking at purchasing the Inovate LC-1 and installing it in the stock location.

I know of one member who is doing this in the stock location with no problems. The main thing to remember is to install it prior to ANY CATS in the exhaust and POST turbo. Also give it some distance from the turbo hotside or it might overheat...

BTW...The included software for the LC-1 is great and it even works great with RomRaider...

I ran mine in the stock location on my WRX w/o any issues.

The issue you may run into is w/ the removal of the rear o2 sensor causing idle trims get off. I read several issues w/ the Sti's having this issue whereas the 2.0L WRX(16bit ECU) did not have this issue.

Anyone running their WB02 in the stock rear O2 location? I realize there will be a slight lag in response time but I am curious what everyone's experience has been running it there.

 

I am looking at purchasing the Inovate LC-1 and installing it in the stock location.

That's the wrong place for a WB.

As far as the other comments on placement, some have doubted the location Cobb chose on their DP, and regretted it. My WB has been permanently installed for over two years in that spot, immediately after the turbo in the Cobb DP without issue. It works. Some apparently think that the turbo creates heat, it doesn't, the engine does, and the stock O2 is closer to that heat than the WB bung after the turbo.

When you say "stock location" be advised that the stock location is in the exhaust manifold prior to the UP. My "stock location" O2 is now in my APS header/UP system immediately prior to the turbo in the UP.

The rear O2 is not the ECU's main O2 input sensor for fuel.

That's the wrong place for a WB.

I would trust a WB company(Bosch) to recommend placement of the sensor over a DP designer. Most, if not all WBO2 companies recommend 12"-18" from the turbo. Its true that the turbo does not 'create' heat, but it is a heat pump w/ a large mass retaining large amounts of heat. The reason I believe the WBo2 companies recommend being ~18" from the turbo is the fact that the heater circuit in the WBo2 is much more critical to the calibration/accuracy of the sensor than say the stock unit.

I have not heard of any problems with installing it in the rear O2 position. If someone has a link to a thread stating there are problems, I would like to read it.

All I know is that wichitalegacy, Airboy, and a few others have installed it in that position without any problems.

If you're not comfortable installing an LC-1, bring it to a Subaru specific speed shop and they should be able to install it for you in the downpipe. BTW, you don't have to hack the ecu harness or anything. Just get a plug.

You would only use the WBO2 for high MAF (> 60 g/s) readings so any lag would not be significant especially if you log near steady state conditions.

There is one advantage (and it's controversial) to using this position. The fake narrowband signal to the ecu allows you to run lean cruise on a 32 bit ecu. The 32 bit ecu does actually use the rear O2 sensor using a statistical algorithm. If it continually sees a lean cruise condition, it will change fueling. I'm not advocating running lean cruise. I just know that it has been done and is only possible on a 32 bit ecu car if a fake narrowband signal is fed to the ecu.

I have not heard of any problems with installing it in the rear O2 position. If someone has a link to a thread stating there are problems, I would like to read it.

 

All I know is that wichitalegacy, Airboy, and a few others have installed it in that position without any problems.

 

If you're not comfortable installing an LC-1, bring it to a Subaru specific speed shop and they should be able to install it for you in the downpipe. BTW, you don't have to hack the ecu harness or anything. Just get a plug.

 

You would only use the WBO2 for high MAF (> 60 g/s) readings so any lag would not be significant especially if you log near steady state conditions.

 

There is one advantage (and it's controversial) to using this position. The fake narrowband signal to the ecu allows you to run lean cruise on a 32 bit ecu. The 32 bit ecu does actually use the rear O2 sensor using a statistical algorithm. If it continually sees a lean cruise condition, it will change fueling. I'm not advocating running lean cruise. I just know that it has been done and is only possible on a 32 bit ecu car if a fake narrowband signal is fed to the ecu.

I have my WB in the "intended" location on the Cobb DP. I did add a heatsink plate just in case it gets too hot. Been there for ~2 years. I bypassed the narrowband rear O2 signal going to the ECU (with LC-1) so that I could fool the ECU into running >14.7AFR in CL. The toggling of the rear O2 signal to the ecu is needed to tell the ECU the cat is still working I think.

I thought the ECU also need to detect the presence of the rear O2 (heater circuit current?)

BTW, this is the advice I gave to Legend.

http://www.legacygt.com/forums/showthread.php?p=1718509

I still think the JDM position is the best place for a WBO2 if you don't mind removing your downpipe. However, I still have not heard of any problems in installing it in the rear O2 position.

The one thing I definitely do NOT recommend you do is ... use an extender. That screws up your AFR readings. Ask Legend about it.

I would trust a WB company(Bosch) to recommend placement of the sensor over a DP designer. Most, if not all WBO2 companies recommend 12"-18" from the turbo. Its true that the turbo does not 'create' heat, but it is a heat pump w/ a large mass retaining large amounts of heat. The reason I believe the WBo2 companies recommend being ~18" from the turbo is the fact that the heater circuit in the WBo2 is much more critical to the calibration/accuracy of the sensor than say the stock unit.

You may, or may not depending on your mindset, find this interesting.

http://www.legacygt.com/forums/showpost.php?p=1720824&postcount=27

If you're not comfortable installing an LC-1, bring it to a Subaru specific speed shop and they should be able to install it for you in the downpipe. BTW, you don't have to hack the ecu harness or anything. Just get a plug.

I have been reading up on the install and it looks pretty straight forward, the only confusion I have is the analog out connection. I am not sure how it connectes to the ECU without hacking the harness?

Get a dead O2 sensor and splice into that plug. Radio shack might also have a plug.

Keep in mind that I have never done this. I've just read on the forums that people have installed the WBO2 in the rear O2 position and it's mentioned in the LC-1 manual.

I know of one member who is doing this in the stock location with no problems. The main thing to remember is to install it prior to ANY CATS in the exhaust and POST turbo. Also give it some distance from the turbo hotside or it might overheat...

 

BTW...The included software for the LC-1 is great and it even works great with RomRaider...

COBB puts their's bung location right at the top of the bellmouth. Are you saying that this is too close or just to close for the LC-1?

OMGWTFBBQ, my wide band has been in the wrong place for 4 years

Are we gong to argue about tire valve caps next? I was planning on using the TPMS ones on a car without TPMS

As I understand the 18" distance, that's 18" from the exhaust port, i.e., at the heads. That's where the most heat is found. Post exhaust port is secondary heat, albeit hot, it's still not as hot as what it was when it exited the heads. And the turbo is also being cooled and oiled so that's pulling off additional heat too, so COBB's (and others in the bellmouth) location may actually be the "ideal" location. Just a thought.

No arguements here...I mounted mine in the same spot as a Cobb DP as well as where the JDM LGT O2 sensor is located as well. If someone has any overheating issues, that can easily be resolved with the copper heatsink..

Removing the rear 02 sensor from the exhaust passage will cause your lgt to run rich at idle and cruise. The 32 bit ecu utilizes the rear 02 sensor for feedback and removing it will skew your fuel trims.

I have tested this a few times to make sure. When tuning customers cars i use the stock 02 location just because i still get a good reading unlike the tail pipe sniffer, but when tuning for drive ability i ake sure the stock 02 is back in place.

What about for a bung install (when you do not use the rear o2 location)? How does the it connect to the ECU?

It doesn't.

The only reason to hook it up to the ecu is that the ecu needs a narrowband signal or else it will cause the ecu to run rich.

I would trust a WB company(Bosch) to recommend placement of the sensor over a DP designer. Most, if not all WBO2 companies recommend 12"-18" from the turbo. Its true that the turbo does not 'create' heat, but it is a heat pump w/ a large mass retaining large amounts of heat. The reason I believe the WBo2 companies recommend being ~18" from the turbo is the fact that the heater circuit in the WBo2 is much more critical to the calibration/accuracy of the sensor than say the stock unit.

+1 That is what the LC-1 manual says. I have mine tapped right before the catt. It works fine for me.