W203 C200 Kompressor - 271940 Engine - Help me with these error codes

[johnsco]

Since the recent engine refit [ Timing chain + sprockets + tensioner + guide ] ... This car has been a dream to drive ...
Today I've just done a quick check over the car.
A scan shows the following codes:
P0036 HO2S Heater Control Circuit (Bank 1 Sensor 2)
P0136 O2 Sensor Circuit Malfunction (Bank 1 Sensor 2)
P0171 System too lean (Bank 1)

As the engine is a straight-4, I guess that "Bank 1" has no meaning.
All the codes cleared without any issues.
Are these things I should be concerned about ?
Is any action recommended ?

The engine is running perfectly.

 

[Dodipops]

Possible oil in the engine harness?
It makes its way from the cam adjusters and manifests itself in the wiring connectors at the o2 sensors if I remember correctly.

Or maybe a small air leak usually the pipe under the air box, if that’s the case the fault will probably return after a run.

 

[johnsco]

Possible oil in the engine harness?
It makes its way from the cam adjusters and manifests itself in the wiring connectors at the o2 sensors if I remember correctly.

Or maybe a small air leak usually the pipe under the air box, if that’s the case the fault will probably return after a run.

Thanks Dodipops.
I sorted these common issues at the same time as the engine refit.
I fitted new cam solenoids and also fitted the additional pigtails to stop the oil wicking thru the harness.
Also checked out the vac lines under the air box.
It will be interesting to see if these fault codes re-appear.