Proper WBO2 Sensor Location

[CFster]

Is there a rule of thumb regarding how far back put the sensor bung? Which side?
I have shorty block hugger headers. In the header or further down the down pipe?

[Danny Cabral]

Wideband O2 sensors can be overheated. The best method is to temporarily run the engine with the WBO2 sensor in each header collector (or slightly farther downstream), note the air/fuel ratios, then permanently install it in the leanest bank for the safest possible scenario. Or just install it in the more easily accessible side, like most people do.
https://forums.holley.com/showthread...ensor-Location (Related Forum Thread)
http://forums.holley.com/showthread....ension-Harness (Read 5th & 6th paragraphs under "Wideband O2 Sensor Notes".)
https://www.youtube.com/watch?v=rmnxKLjM25g (Wideband O2 Sensor Test/Diagnosis - it works!)

[S2H]

It's hard to overheat them, so it's highly unlikely.

One other rule of thumb is to get them about 12"-18" from the collector, to allow exhaust pulses to merge together, so you aren't getting odd readings from just one primary. And you want at least 18" of pipe after the WBO2 so you don't get false readings from fresh air entering the exhaust.

Also, position is important. Try to get the WBO2 as close to the 12 o'clock position as possible as moisture sinks and will destroy an WBO2 sensor instantly if it gets the sensor wet. Keeping the WBO2 sensor up on top of the pipe, keeps the moisture contamination to a minimum.

[Danny Cabral]

It's hard to overheat them, so it's highly unlikely.

I'm glad you & I have never overheated one, but it does happen.
The WBO2 sensor temperatures are specified in this product description:
http://www.innovatemotorsports.com/x...cat=250&page=2 (Innovate Motorsports HBX-1)
I've been using HBX-1 Heat-Sink Bung Extenders for many years (dual WBO2 sensors).

If the yellow AFR/WBO2 status LED isn't being activated, it's OK.
http://documents.holley.com/techlibr...__statuses.pdf (Holley EFI Sensor Diagnostics & Statuses)
S2H's WBO2 sensor location & position information is very good advice.

[centrifuge]

Has anybody ever put a WBO2 sensor in a turbo header (pre-turbo)? If so what was the result?

[Danny Cabral]

Has anybody ever put a WBO2 sensor in a turbo header (pre-turbo)? If so what was the result?

WBO2 sensors can't be used in a (pre-turbo) high pressure/high temperature location due to false readings.

Dual WBO2 sensors can be used on naturally aspirated, twin turbo, supercharger & nitrous oxide applications.
Dual WBO2 sensors can be also be used on single turbo applications; one used to verify the other (and on some rear mounted turbo applications).

[ButchB]

WBO2 sensors can't be used in a (pre-turbo) high pressure/high temperature location due to false readings.

So, the wideband O2 needs to be after the turbo?
If so, and my downpipe is only about 18" long, is that gonna cause any issues?
The car is a track car and it'll be a 5" DP ran from the turbo straight out the fender.

[Danny Cabral]

So, the wideband O2 needs to be after the turbo?

Yes.

If so, and my downpipe is only about 18" long, is that gonna cause any issues?

I highly suggest using Holley's 554-100 NTK WBO2 sensor.

[ButchB]

Yeah, I'm gonna run methanol, and from what I've read, that's the WBO2 sensor I need to use. I guess I'm just concerned about how close it's gonna be to fresh air being on the downpipe side of the turbo.

[S2H]

As long as you have no exhaust leaks, you should not be concerned. There is no fresh air on the downpipe. The downpipe is exhaust passing through the turbo. Proper exhaust gaskets between the turbo & downpipe, and the rest of it welded up properly or clamped properly, you shouldn't have any issues.