How to get out Lambda Sensors?

[L10 TVR]

Help, trying to change Lambda sensor but how the hell do you get it out. The nut's too far down, to get a spanner onto it and a socket won't get over the wires?

Also if I disconnect my Lambda sensor shouldn't I get a fault reading up on the fault box?

[Midnight Blue]

As quinny says, a box spanner is the way forward. I had to buy a cheap one, then hacksaw a long slot up one side to let the wire out.

There is a commercial tool to do this, but the Lucas sensors that TVR use are not the standard size. (typical)