9 replies to this topic

[DUF2]

I want to use an Air Fuel Ratio gauge on my ‘89 Metro 1275 engined Elf

I don’t want to make a permanent fitting so can I just rig this up by pushing the sensor up the tailpipe?

[Rubbershorts]

I want to use an Air Fuel Ratio gauge on my ‘89 Metro 1275 engined Elf

I don’t want to make a permanent fitting so can I just rig this up by pushing the sensor up the tailpipe?

I think the general consensus will be no, not really. You can have the boss welded to your manifold/exhaust though and cap it off when you unscrew the sensor after use. Daz.

[timmy850]

I have one of the Innovate tailpipe adapters. It works well while driving, but doesn't give readings at idle

 

Later I got a bung welded into the exhaust 

 

https://www.innovate...aust-clamp.html

[Minuki]

Fit it correctly, i.e weld the bung in and wire it all up. Once you're happy with how it's running, take the sensor out and fit a blank into the bung then you can either leave or remove the wiring. 

[68+86auto]

There will be no way to know if the readings can be trusted or not as the sample can be diluted. That's the problem with any single gas measuring device, especially one like that which is based on O2.

I'd rather use an ancient wheatstone bridge type analyser than an O2 sensor.

Edited by 68+86auto, 15 July 2026 - 11:53 AM.

[Steve220]

If you're just doing it on the drive, you can use a sniffer pipe. But if you want something for when driving, personally i'd put a bung into the bottom of the exhaust manifold, do your tuning, then put a blank in.

[DUF2]

I have not uploaded any pics for a while. I now find I can't do this! any ideas why?

[timmy850]

If your TMF+ subscription expires you can’t attach any more images. You can either renew your subscription or use a third party website like imgbb

[DUF2]

back to the AFR gauge fitting.

I only intend to use the gauge on a temporary basis, I do have a boss and will eventually get the fitted to the front pipe.

in the meantime I will try pushing the sensor up the tailpipe, as can be seen in the picture the sensor lead should go up the tailpipe around 400mm.

It is the wiring I am struggling with, the gauge was a cheap internet buy and the instructions are 5hite. The sensor has 4 wires, one grey, one black and 2 white. The gauge has 4 wires 1 red & 1 yellow, which go to ignition switch, 1 black which goes to earth and finally 1 green which according to the instructions goes to “ O2 sensor wire”

 

anyone know how I should connect these Please?

 

 

[Ethel]

https://www.wbo2.com...le/lsuconns.htm

 

I suspect the  "sensor wire" is a narrow band signal for if you replace a narrow band sensor used by a fuel injection motor.

 

There might be a connection to the sidelight circuit for illumination. Otherwise I can't see it needing more than (ignition fed) power and earth to the vehicle wiring. Perhaps a permanent live if it has a memory function.

 

Don't think just pushing it up the tail pipe will work if you mean literally

 

https://dtec.net.au/...robe Design.htm

 

https://www.ebay.co....:Bk9SR6LSu5r-Zw