below link explains the code meaning etc,Hi All,
I have a Mini Cooper R56 with a standard 1.6 engine.
The car keeps throwing up a P0420 code and some people have mentioned a small amount of Blue smoke (however, I haven't seen this myself)
The cat and o2 sensor have been changed but the code keeps coming back, any ideas where I should next be looking?
Is the Blue smoke related to the P0420 code?
if car north of 60k timing chain and if blue smoking then oil has prob dmaged the cat and 02 sensors valve stem seals very common