Oil Separator replacement

I thought I'd just my experiences with this job add this in case anyone else has this problem.

I have my daughter's visiting with the grandchildren and the Fabia is up for the cruise control fitting, a service and an MOT. It had a 'Too Lean code' stored. It is a 2016 1.2 CJZD 4 cylinder

2821 - Bank 1; System Too Lean off Idle

P2177 00 [01100000] - -

Intermittent - Not Confirmed - Tested Since Memory Clear

They live 300 miles away so I try and fix everything I can while they are here. @Crasher kindly suggested the oil separator as a good bet being a fairly well known fault for this code so I took a chance and fitted one. https://www.skoda-parts.com/spare-part/04e103464am-oil-separator-skoda-35930.html I couldn't see anything wrong with it but the new separator (which is essentially a plastic box with a rubber pipe connection) did have an updated part number. I forgot to order a new rubber seal for it so I added a smear of Permatex Grey which is very similar to VW's sump/gearbox sealer around the old seal which looked to be in perfect condition.

The code/EML hasn't returned (although it was intermittent so the jury is out) but it has cured the poor idling/chugging, almost stalling on first start up in the morning so I'm fairly hopeful.. 🤞 I presume it must have been PCV air leak leading to unmetered air entering the system.

The job is pretty awkward and not recommended unless you are very patient! It's at the front of the engine roughly below cylinders 1 & 2. There is a close fitting cover over the separator which snaps off on release of four plastic clips. This is fiddley enough but then there are eight Torx bolts in the separator to get out. You need the correct length Torx bit and nimble fingers to reach the top ones!

There are lots of reasons for a 'Too Lean' code including the O2 sensors so I know it was a bit of a punt.

Edited 30 August, 202530 Aug by Rheumy