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air/fuel gauge bung (sensor) position

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#1
BlueJay73

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Where on the exhaust downpipe do you put the bung for the A/F gauge sensor?

Do you go through the pipe at the area of where the heat shield on the downpipe is, or further down the line past where the heat shield on the downpipe ends (but before the flange where the muffler connects to the downpipe)?

Thanks,

Jim

 



#2
Brandon

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While installing a replacement O2 sensor, I just noticed on mine the aftermarket AFR sensor was installed in the stock bung and the new bung was welded an inch upstream with the PCM sensor installed there.

 

Best guess on their reasons was: stock location is far enough from the ports to be accurate (for the aftermarket sensor/gauge) while the stock one was be welded just a bit closer since it's not looking at much of a variation to adjust fuel-air mixture.


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#3
38bfast

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Read the recommended installation directions that comes with the gauge. 


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#4
luvin_the_rings

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Read the directions. 

 

Most wideband O2 sensors can't operate as high as a narrowband sensor that comes from the factory, so its necessary to mount it further back toward the drivers seat.  

 

Also, make sure its pointed down a little bit so water can't collect and pool up in the sensor.  



#5
Jim Drago

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tough crowd, who has time for directions when you have a forum :)

 

They are all off anyway.. :(  I find most are off on average.4-.6, some alot more, very few any less.  Meaning your sensor should say 13.0 and it will likely read 12.4-12.5.. Please factor that in to your a:f adjustments which should help you from melting down your engine?

 

Jim 


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#6
BlueJay73

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Thanks. Any comments are helpful. Directions were generic (no closer than 18 inches from exhaust port, to at least 36 inches away in situations with hotter temps--turbos, extended high RPM cars, etc.). I was asking the Miata guys where their A/F sensors were placed on their Miatas.



#7
Steve Scheifler

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My experience is not quite the same as Jim's in terms of accuracy, but assuming you tune for power on the dyno and keep track of the range that your gauge is reading at several RPM, at least you will know what to look and shoot for if something changes at the track.

There are few good options for where to install simply due to limited clearance. Even though a bit close we place them in the downpipe where they can be R&R'd from the wheel well.
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#8
BorisB

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What year car ?


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#9
BlueJay73

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Car is a '99.



#10
BorisB

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Why not just bolt it in where the stock one was ?

You don't need the stock one


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#11
Steve Scheifler

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Why not just bolt it in where the stock one was ?
You don't need the stock one


Oh? Have the rules changed?
I've long thought we should be able to use one of the available dual output types with one channel mimicking a stock sensor, but as far as I know it is not allowed.
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#12
FTodaro

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I am not sure the rules are clear about replacing your stock sensor with an aftermarket O2 sensor. As they do not say you can, so its not legal.

 

If you do replace the original with the aftermarket you will have to wire it to the computer as the stock one and split the signal to the the gauge.

 

I installed my 02 sensor on the top of my down tube at the 12 o'clock position just past the fill plug on the trans so i could get to the fill plug. I have not had a sensor fail at that location in the 4 years i have been running them. 


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#13
davew

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They are all off anyway.. :(  

 

Jim 

 

Are you referring to the AFM gauges or the people responding to this post?????


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#14
Jim Drago

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Are you referring to the AFM gauges or the people responding to this post?????

the gauges..  we all knew the people are a little off in general  :)


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#15
callumhay

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Where on the exhaust downpipe do you put the bung for the A/F gauge sensor?

Do you go through the pipe at the area of where the heat shield on the downpipe is, or further down the line past where the heat shield on the downpipe ends (but before the flange where the muffler connects to the downpipe)?

Thanks,

Jim

If you are in the market for it, I'd recommend buying a performance exhaust with the bung installed. Makes life really easy to do it that way, especially if you are not a welder. I have the Kooks exhaust that Dave  W sells and the location is almost the same level as the stock O2 sensor for emissions ( to the right of you while you are sitting, maybe 3/4 way back in the transmission tunnel in my 99).  I think the springfield dyno has one too (IIRC). As you probably know, if you disconnect that O2 sensor, you get a check engine light. I hooked up a new sensor and tied it up away from anything that it might hit to cancel the light.   

 

Cal



#16
luvin_the_rings

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We went through 2 sensors when placed in the stock location on the 1.6  Its in the header collector area.  They got too hot.  Once we placed the bung further back at the end of the down pipe, the failures stopped.  



#17
BlueJay73

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Thanks all.

Looks like 12 o'clock in the vicinity of the transmission drain plug is a good spot.

Can pull the wire up through the shifter hole and run it behind the dash to the gauge.

Taking off the downpipe is not fun. Those 3 bolts look accessible, but they're not.

 

Jim



#18
Ron Alan

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Thanks all.

Looks like 12 o'clock in the vicinity of the transmission drain plug is a good spot.

Can pull the wire up through the shifter hole and run it behind the dash to the gauge.

Taking off the downpipe is not fun. Those 3 bolts look accessible, but they're not.

 

Jim

I found with an extension and a hole saw bit I can reach up and drill a hole that comes through right behind the radio bezel(tombstone). I drill a hole big enough that the sensor can go through but a size that allows me to use one of the old rubber grommets from the firewall(or whatever you can find at the auto parts store). Drop the sensor through then split the rubber grommet around the wire and snap it into the hole...wire protected! This leaves the big plugs from the sensor and the gauge ready to plug in and they hid behind the radio bezel!

 

BTW...my sensor is in the first 6" of my SD exhaust...which comes out lickety split! No need to touch the down pipe!


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