below link explains the code meaning etc,
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
https://exhaustsystemsguide.com/p0420-code/
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?
first need to check the basics, ie oil pressure and compression on it as no point repairing the top end on a engine with oil pressure as would need to do the whole motor which will be a lot of money engine out job, the valve stem seals are common and will need a valve compression tool and a magnet and vaseline jelly ie makes it easier to get collets back on the valve stems ends to lock the spring,, also need a timing chain locking kit, torque wrench, and i use tipex to mark things like head bolts and cam shaft bolts to know at what stages i'm at when doing them up as head bolts have 3 stages.That is what I was suspecting from reading about this.
Is there any guides on changing these?