Diesel Cat Converter and Lamda Sensor..

[psmart]

Does anyone know why a 270cdi found in an ML doesnt have a Lamda sensor (other than the assumption that diesel burners always burn air rich, not fuel rich).

Also, anyone have a rough idea how long an ML pre-cat and 2nd-cat last for in terms of years/mileage?

 

[enscjb]

The lambda sensor isn't part of the standard control system for a Diesel, as you say they always run lean. The main job on a petrol is to put exaclty the right amopunt of fuel in to keep the combustion stoichiometric (Lambda=1). For a Diesel you can put as much fuel as you want in so long as it isn't too smoky, too hot, or PMax isn't exceeded.
Chris