Found it…

[Neilb62]

Keep getting a code for bank two lean, so I bought myself a cheap smoke machine from Amazon not hoping for much. Can’t be the intake trunking as I only replaced it last year I thought….
So much for that then!
When I fitted the new one I’ll look for more as I can’t see that affecting only bank two?

 

[ChrisD]

Keep getting a code for bank two lean, so I bought myself a cheap smoke machine from Amazon not hoping for much. Can’t be the intake trunking as I only replaced it last year I thought….
So much for that then!
When I fitted the new one I’ll look for more as I can’t see that affecting only bank two?

The rich/lean DTCs are threshold based. It could be that both banks are very lean but only one is above the threshold. Fix what’s in front of you and re-assess afterwards.
Good luck with getting it resolved.