I am going to be adding a wideband to my car in the coming months, and I currently have a narrowband o2 sensor in the stock location. I have read Grumpy mention "missing the tune" multiple times, and I know that it's good to have a narrowband to compare to the wideband's output to eliminate erroneous data due to ignition timing, etc.

So with that said, should I put the WB02 in the same bank, close to the stock sensor? When I built my exhaust I welded a bung into the passenger side exhaust tube because I found a good place for clearance and figured it would be closer to the ECM, less wiring to run, etc. Now I am second guessing that decision. Both banks should be very close to each other barring any ignition or fuel injector problems, so I don't think it will really matter....

Am I overthinking this?

 

Innovate wants it as far away as possible. I put mine right before the cat.

Any and every exhaust leak will make the wideband read way off.

When you fix all that, and the wideband reads right, you'll find that it doesn't really matter what it reads cuz every m otor likes a different AFR, so all that money just went into something that just tells you if your stupid rich, or stupid lean.

-- Joe

 

It depends how much time you have on your hands. I put 2 O2 bungs in each downpipe so that I can run a WB & NB in each side at the same time. I can mix it up however I like. This is more of an educational setup.

 

I have dual cats, so I'd still be putting it on one bank or the other. My bung is probably 6" from the collector on my SLP header, and I'm pretty sure my exhaust is leak-free since every connection is either welded or flanged. I know every engine likes a different AFR, but don't you think that for around a couple of hundred bucks, the extra margin of safety in tuning is worth it? Not that I enjoy wasting money. I would also like to tune for a bit more MPG in lower load areas, and this should help me there as well.

Spare time.. what is that? Heh.

 

I'd suggest putting bungs on both sides. I started out with the NB on the left and the WB on the right and could never figure out why the WB was reading 1.0 AFR or so richer than the NB. Even sent my WB stuff back to have it checked (it was fine they said). So I moved it to the left side after the NB and low and behold, it is reading correctly. I've currently got a WB on each side, on with an LED display that is also tied into the ECM for datalogging and the other just with an LED display for comparison purposes.

So now I have to figure out why my right bank runs so much richer than the left with my SuperRam. Swapped to known good injectors, sealed everything with RTV so shouldn't be a vac leak (altho I may do it again just to be sure). Got to verify no exhaust leak on left side since that could draw O2 in ahead of the NB and drive the pulse widfh up. Only other thing I can think of is the IAC feed and the general air distribution inside the SR plenum (have no idea how to fix that!).

Wish there were more folks with a WB on each side just to see if this split BLM kind of thing is all the common, especially with a SuperRam....

 

I've got a different setup, but the same problem. Not sure what to do, so for now I'm just living with it. For now it runs good, etc... It may just be an idle thing (like your IAC suspicions). The WB readings at WOT are pretty consistant, so one of my next steps will be to switch the WB to the other side, and do some runs to see if the numbers match up. If they do, then it's definately some vacuum leak (like the IAC). When I get the energy to investigate it further, I'm sure I will.

 

Sounds like a Split BLM issue. If you look at the LT1 boards you will see that is a well known issue. The problem is basically a mechanical problem as well as the fix. My theory is that the TPI boards do not necessarily know about it because they don't log both sides at the same time. Now that you logging both sides you are seeing it and just as you said at WOT it evens out. I have setup my car for 2 O2's one for a NB to run the computer and the other for a WBO2 but I have not logged that way yet as I am using my WBO2 for both duties and been too lazy to get under the car and finish the job. I did do the TB fix and IAC bleed hole to get most of the idle air through the hole. Try adjusting your TB at idle to see if you can get both sides in line by opening and closing the blades while datalogging both sides. The rule of thumb that seems to work is your IAC counts should be around 30-40 steps. Note the steps in $8d are around 50-60 at normal temps and idle. You may be able to solve the problem by doing that alone. If not a IAC bleed hole would be the next step but that is more for a LT1 intake with idle holes in the runners. The problem could also be a leaking exhaust, reversion from large cam or just one side of the motor favoring the other side based on how it is breathing all the air in the plenum.

 

Thanks for the reply and suggestions. My problem is I'm seeing the difference at cruise as well as at idle. 1.0 to 1.2 AFR richer (lower AFR) on the pass. side. Have not logged a WOT yet with both WB's installed. Currently my WB datalogging is reading the driver's side. Figured that was the leaner side, so I wanted to watch it so I wouldn't get too lean and burn a piston.

Sounds like the TB drilling really won't do anything for a SuperRam. So I'll hold off on drilling my BBK.

I'm ging back to verify no exhaust leak on that driver's side, as well. Looking at my SR plenum, I can see how the air distribution could be off, it's definitely not a symmetrical set up like normal TPI, the HSR, Miniram, and LT-1 intakes are. That could be the whole problem.

I'm going to pull some plugs this week (again) and see if they show the richer condition on the passenger side. If not, then it almost has to be an exhaust leak somewhere on the driver's side letting the extra air in ahead of the O2 sensors.

Make sense?

 

Yes I agree. You can benefit from logging both sides. Split BLM's are mechanical in nature so if you can log it and find a problem that you fix then it was wothwhile. Personally I would still try adjusting your TB blades first to see if it changes anything. If it fixes it or gets it closer then your done with a quick fix. Next I would check the headers to make sure they are tight. The IAC hole fix is down the line from the blade adjustment...

 

I agree. Will try your ideas first. THANKS!