Where do you (or will you) install your WB O2?

[Sendero]

I am in the final decision making process for buying a WB O2 setup. Recently, I have seen some discussions on where to mount the O2 sensor in relation to your non-WB O2's. The main concern is "sensor shadow" where the WB O2 can't do its job because the NB O2 upstream is causing turbulance. I don't know if I quite believe that, but thats why I am asking you guys.

I will be keeping both NB O2's in their stock locations because the NB emulation on most controllers is two slow for the EEC computer to overcome. The car has a Dr. Gas X pipe without the cats. I was planning on mounting the sensor horizontally on the outside of one of the downpipe legs.

Specific Questions:

When they say 24" from the engine block, do they mean the back of the block or the last exhaust port?
What about "sensor shadow"? Is it a valid issue?
Where do you have yours mounted?

[QWKSNKE]

If I decide to go that route (I have entertained it a couple of times), I will probably mount it a foot or so from the front driver's side OEM 02 sensor.

[EZ SPEED]

When they say 24" from the engine block, do they mean the back of the block or the last exhaust port?
What about "sensor shadow"? Is it a valid issue?
Where do you have yours mounted?

Everything I read said "18" min. from the exhaust port. (same difference)

I mounted mine in the second bung that my aftermarket cats have.
My Cats have a bung before the cat brick and a bung after the cat brick.

I know a few other Lightning owners that use this same location without a problem, so I am gonna try it here unless I feel like it is giving false readings, or later on I might move it upstream a little.

[86GT]

It also depends on the type of WB. If it is the Bosch then I believe it has some min and max distance that it can be from the exhaust valve. I think the max is around 25 inches. I got the info from PLX.

It does seem kind of weird that PLX would state this when the O2 sensor has a built in heater. It is most likely to save on the heater time.

When I installed mine I had them welded in about 2 inches downstream of the factory ones and clocked a bit. Here is the catch, After the welding was done and a couple of days went by, I heard some rattling. It ended up being slag inside from the welding that had broken loose.

I was so pissed that I had to completely remove the H-Pipe (with cats) and shake out all of the remaining slag. I also at this time used a long screw driver to reach down inside the pipes to break off any other slag.

If you can have it welded off the vehicle.

[86GT]

Everything I read said "18" min. from the exhaust port. (same difference)

I mounted mine in the second bung that my aftermarket cats have.
My Cats have a bung before the cat brick and a bung after the cat brick.

If you mount it in the second bung (the one after the cat) You will get false readings. I tried it, and mine differed by about .3 AFR

[Sendero]

I see Lee said Drivers side. What about Clint and Eric, which side?

Does it matter?

[86GT]

I see Lee said Drivers side. What about Clint and Eric, which side?

Does it matter?
I had a bung welded on both sides. I have the WB in the drivers right now.

[EZ SPEED]

If you mount it in the second bung (the one after the cat) You will get false readings. I tried it, and mine differed by about .3 AFR

Yep, I know ...But, I can live with .3 compared to some Yahoo screwing up my beautiful stainless exhaust (headers alone are about $800)
And its closer to being correct vs the tailpipe sniffer at the Dyno. ;)

Nathan....Drivers side...but I can also use the passenger side also.


Just for the sake of saying....

Some people turn off their rear O2's and use one of those bungs for a readout, but it would also be off a little depending upon the cats and distance.

[QWKSNKE]

I see Lee said Drivers side. What about Clint and Eric, which side?

Does it matter?

I said driver's side because that is the bank that is usually the leanest (if that is a word. lol) on a pushrod. Don't know about mod motors :shrug:

[coupe]

Well, it's bound to do better than the sensor used for a dyno test...shoved up the tailpipe! And that does pretty well for street tuning. Stick it somewhere accessible where the pipe goes down under the car. Either side is probably ok.

[Italian LX]

It does seem kind of weird that PLX would state this when the O2 sensor has a built in heater. It is most likely to save on the heater time.
I'm pretty sure that you are aware of this, but the stock O2 sensors have heaters too. It's only used to cut down on initial heat up time; not sufficient enough to heat the sensor to proper operating temperature. :nice:

[tacbear]

If I'm not mistaken, Dave said for me to mount mine in the passenger side rear O2 bung after having the rear sensors turned off (mod motor)

[93Cobra#2771]

I'll be mounting mine same as Clint (if I ever get one) - slightly downstream and slightly clocked from my stocker.

There was a big thread on the tweecer mailing list about shadowing - I believe the end result was there was no shadowing effect, but I still plan on clocking mine around a little just in case...