do i need a special tool to replace a lambda sensor on a nissan micra x reg?

you need a normal spanner.

Mr b Dover
November 2009

Possibly, it depends on the position of the sensor.
You might need one like this-

http://www.fast-tools.co.uk/acatalog/Exhaust_Lambda_Sensor.html

or like this-

http://www.tools-n-all.co.uk/Laser-4257-Lambda-Socket-Spanner-Wrench-Hex-Tool?CAWELAID=154256841

Make sure you get the correct size, most seem to be 22 mm., but some are 17mm.
You should be able to get them from a decent local motor factor or tool shop.

some general info here-

http://www.lambdapower.co.uk/technotes/fitting_guide.asp

laguna
October 2009

There is a socket that certainly makes the job easier...it is open on one side to allow for the wires to be accommodated when the sensor is unscrewed. It all depends on how easy it is to access the sensor, and how tight it is, really.

John
October 2009