Oxygen sensor boss size

[steve-V8s]

It seems that the standard TVR sensor has a different size (smaller) boss than the norm. I plan to use a narrow band sensor on one side and a wide band the other for AFR metering. But would like to have the option of swapping sides. I know some of you are doing the same thing so what have you done about the boss size ? Presumably I could change the boss both sides and buy one wide band and one narrow band. I have heard of people using a wide band mounted in the small boss with some sort of adapter, that way I can leave the manifolds standard. Anybody got experience of the adaptor method?

[GreenV8S]

I have a boss for a wideband sensor on both sides. I only use one side and I have a blanking plug in the other. The original narrowband bosses are still in place and have narrowband sensors fitted just to plug the holes. (I assume the sensors are U/S by now but if I had wanted to preserve them I would have put plugs in there too.)

[Johno]

I removed the narrow bands and plugged with s/s cap head's. Then put the wideband into the Y piece (ACT de-catted) behind the expansion tank.

[dnb]

You can get narrowband sensors that have the same M18x1.5 thread size as the widebands, and they are cheaper than TVR sensors.

[adyw]

The LC-1 I have fitted is 3/8 NPT thread

[clive f]

most wideband are m18 x1.5mm thread.

but yank origin may be different.