Hi all, The other day cel came on called green flag and the read the fault and it was bank 1 running lean. Cleared it no cel but thought I out to get the car logged to be on the safe side. Logs all fine fueling as it should and all seems well. Checked for faults today and low and behold bank 1 running lean at idle and now boost pressure regulator not reaching boost. Garage have checked the lambda readings and they are normal. I've changed pcv to latest revision and dv to g last year Car is a tfsi running stage 1 . Are the codes linked or two separate faults anyone got any ideas?