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Mini Engine Problems Blue Smoke and P0420 code, but cat and Sensor replaced

3538 Views 3 Replies 2 Participants Last post by  mike1967
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?
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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?
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/
That is what I was suspecting from reading about this.

Is there any guides on changing these?
That is what I was suspecting from reading about this.

Is there any guides on changing these?
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.
also will need sockets 1/4 drive set with extensions etc is very handy for the nuts on the exhaust manifold as these can be a battle as need to remove the studs if not removing the cat, and will also need a torx set on sockets and bits,
links below worth a look at i know its on a n14 both heads are same thing except your non turbo one will have twin vanos and is not direct injection, but all the rest of the job is the same,
https://www.youtube.com/watch?v=PPoU6iAIhlc
https://www.youtube.com/watch?v=Wh3sK3Vnv_g
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