Wideband sensor location

Headers, cats, uppipes, downpipes, midpipes and mufflers.

Moderators: Helpinators, Moderators

Post Reply
zeke
First Gear
Posts: 128
Joined: Sun Jan 22, 2012 8:16 am
Location: Yakima WA

Wideband sensor location

Post by zeke » Tue May 29, 2018 9:57 pm

So my wideband sensor is on its way I was wondering if the stock narrowband location is a good spot to put it. The new one comes with a weld in bung if its not, also if I put the bung in someplace else is there any advantages to running a wideband along side of the narrowband? I am using a haltech elite standalone also.

Sent from my XT1650 using Tapatalk
91 ss Ej22t dohc td04 sti Slanty haltech elite 1500

dankberries
Second Gear
Posts: 480
Joined: Thu Oct 27, 2011 5:09 am
Location: Dirt Roads, Colorado

Re: Wideband sensor location

Post by dankberries » Wed May 30, 2018 6:22 am

From the haltech website:

Broadly speaking there are two different types of O2 sensor available, wideband and narrowband. Both sensors have their place in tuning an engine, narrowband sensors are designed to be used in conjunction with a catalytic converter.

In brief a catalytic converter works on a saturate/starve principal where the fuel injection system saturates the converter then starves the converter, i.e. it runs rich of 14.7:1 (saturate) then lean of 14.7:1 (starve) and as such a narrowband O2 sensor only reads rich of 14.7:1 or lean of 14.7:1.

Unfortunately a narrowband O2 sensor is unable to determine exactly how rich or exactly how lean the engine is running making it useless for full power engine calibration (as under full power we need to run the engine much richer that 14.7:1 so we don’t melt pistons!).

A wideband O2 sensor on the other hand is designed to read a much broader spectrum of air to fuel ratios (The Haltech CAN wideband reads accurately from 10:1 – 20:1 air fuel ratio) which makes it the ideal tool for engine calibration.

Narrowband or Wideband?
For engine calibration purposes, diagnostic purposes, datalogging and performance work a wideband O2 sensor is the correct tool for the job. For emissions related purposes used in conjunction with catalytic converters a narrowband O2 sensor is essential (normally with a wideband O2 sensor in place as well for the full power engine calibration).


In my personal experience I've opted to use only wideband. I've also had no problems with emissions doing so.

As for placement of the wideband o2 sensor the general rule of thumb is no closer than 5in. From the turbo to maintain longevity of the sensor. I personally place mine at the end of the down pipe, most aftermarket down pipes for Subaru have a bung mounted 24 or more inches at the end of the down pipe. Its also been noted by many wideband o2 sensor manufactures that the bung should be mounted at an angle towards the stream of flow rather than straight up and down..
93 impreza rally muffin
93 legacy ss Tarmac Terminator
89 Nissan 240sx sr20
90 Nissan 240sx 2jz
killajamal wrote:Dank is actually German for "silly term which the kids have come up with to describe exceptionally choice marijuana.''

zeke
First Gear
Posts: 128
Joined: Sun Jan 22, 2012 8:16 am
Location: Yakima WA

Re: Wideband sensor location

Post by zeke » Wed May 30, 2018 6:30 am

Yeah I've read to not put it up and down too. I don't have any catalytic converters on my car anymore and no emissions testing where I live. Looks like I have some welding to do when it gets here.

Sent from my XT1650 using Tapatalk
91 ss Ej22t dohc td04 sti Slanty haltech elite 1500

Legacy777
Site Admin
Site Admin
Posts: 27483
Joined: Tue Oct 15, 2002 11:37 am
Location: Houston, Tx
Contact:

Re: Wideband sensor location

Post by Legacy777 » Tue Jun 05, 2018 6:00 pm

I'll give you my take on things; the issue with putting further away from the engine (end of the DP vs. top) is the delay in readings. Under steady state tuning it wouldn't be an issue, but if you're using the ECU for real time tuning adjustments closer the sensor is to the engine the better.

I have my wideband in the stock O2 sensor location. I have replaced the sensor once over the life/years I've had the wideband installed.
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
1997 Impreza OBS

If you need to get a hold of me please email me rather then pm

Post Reply