[JVS]

Nah it's not clipped. If you look closely I think you just loosen the sensor. Just at the header pipe/sensor connection you'll notice a nut type thinggy. Just loosen that with a spanner and it should come out. I haven't done it but that's what I think we have to do.

Other members such as hobbydad or anyone else that have replaced the header pipe may confirm this.

edit - Come to think of it, if we do start unscrewing the nut, the wires will also start to spin/tangle at the back. Damn, i'm not sure avandr. Let's see what other members have to say.

[2bikebill]

Just unscrew from the header pipe and refit to the new one. If you're lucky, your bike will have been assembled by the one with the brain cell, who will have twisted the wire the other way a few times before screwing it on. Just make sure the wire is twisting evenly to a few inches back as you unscrew, and not into a tight bunch near the fitting.

[hillntx]

I haven't had to do it, but I would recommend disconnecting the sensor before trying to remove it from the header pipe.

[foggy95]

I just installed the Hitchcock header on my C5  a couple weeks back. I too thought I would have to disconnect the 02 sensor, but it's not necessary, and I didn't.

Unscrew the sensor from the original pipe, this process will twist the wires since the other end cannot move, but the wires will not twist too much, there was no fear of them breaking, etc. When re connecting the sensor to the new pipe, I 'pre-twisted' the wires before attaching the sensor to the new bung. This allowed them to 'untwist' as I turned the connector into the new pipe. I experimented a couple of times as to how many 'twists' it took so that when fully tightened in, the sensor wires were completely untwisted when tightened down.

Sounds more complicated than it really is.

[Arizoni]

Knowing how robust the wiring on a Royal Enfield is it might be a good idea to remove the fuel tank and find out where the O2 sensor plugs in.  I don't know how long the wire is but mine has a rubber sleeve protecting it and I'm sure it wouldn't permit very many turns of the sensor before it was wound up tightly.

While the tank is removed you will have good access to any of the other wiring connectors that may be lurking up in that area.  Make sure they are all plugged in securely while your there.

Even a wrap of plastic electrical tape around the connectors might not be a bad idea and it may keep unwanted wetness out of the connections?

[gremlin]

....................Even a wrap of plastic electrical tape around the connectors might not be a bad idea and it may keep unwanted wetness out of the connections?

The RE connectors are simple spades without weatherpac connectors.   A wrap of tape (counterintunitively) may actually work to trap moisture instead of barring it.

I'd suggest opening each connector and greasing the connections.  The grease will  be an effective H20 & O2 barrier.