Plugs fine / Lambda very black

[BRUN]

touch wood at present im ok, however, ive been thinking back to when i went through a lambda sensor in 4 months !

why would my lambda look like this, if my plugs are fine, normal brown colour
http://i5.photobucket.com/albums/y186/mbrunskill/lambda.jpg

ttp://i5.photobucket.com/albums/y186/mbrunskill/plug4.png

[BRUN]

FFS @ no edit button
http://i5.photobucket.com/albums/y186/mbrunskill/plug4.png

[number1]

Plug looks about right to me, i havent seen a clean lambda yet, think the carbon in exhaust fumes makes it look like that

Dave