Breezy_Pete

While looking at what part numbers to search, I did note that there appears to be two versions, of which the newer one isn't apparently just a supersession of the older (A-suffix). So avoid sourcing from cars that are earlier than MY2003. The changeover was some time in MY2002 (tenth digit of VIN=2). No idea what difference there is but both variants are discontinued:

Dunno if they really have availability, or if you were thinking of spending serious cash to solve this, but LLL parts seem to have new genuine available: 6Y9860025C and Skoda Roof Rail 6Y9860026C - LLLParts both there.

The prefacelift ones seem to hardly ever fail, in comparison to the later ones.

2nd and 3rd images here suggest Mahle is an OEM on this part: https://www.ebay.co.uk/itm/265058476573

Oh, wait, is his pre-facelift? If so window motors not so useful.

Driver's one particularly.

It seems not. Hmm. Any history of trouble with heater matrix leaking? That's immediately above the airbag ECU.

I'll look at the circuits shortly. I wonder if these items share an earth, spliced into the main cabin loom somewhere that might get damp...

Sorry, must have looked too quickly, as I thought I'd seen both faults swapping sides. No idea what connectors there are peripherally, but I think the airbag ECU is pretty unlikely to get damp in its location, so start at crash sensor and seatbelt reel. Where is the relevant crash sensor? Water ingress tend to leave green crusty corrosion products on copper wire and connector pins.

Looks to me like the ECU you bought may be for a LHD car, so it thinks right side is passenger side? Always best to stick to exact part number matches including suffix, unless you have concrete information as to compatibility. You should be able to clear airbag faults with VCDS (including the freeware version VCDS Lite, which you can download from ross-tech.com). Then a cheap (<£20) KKL cable to connect car to laptop and you have tip-top diagnostic capabilities. You'll have to find and fix the problems first though, which I would hazard a guess as being corroded wiring connections.

Depends on your health and lifestyle today, probably.

Can't mark it up just now, but at the ends of the long bit!

Near the ends of the transverse part of the rear beam.

I think the Citigo compressor may have a clutch, judging by ebay pics of what I think your compressor part number probably is (1S0820803B). That is pretty unusual for modern Skodas though, most have instead a solenoid valve that varies the displacement of the pump from some minimal figure of say 4% up to max. Not sure how to go about fault-finding, but the relay associated with the compressor is in position 10 of the relay holder in front of your right knee when sitting in RHD driver's seat.

Finish the diagnosis. Chances are high that valves will have been bent if chain has slipped on crank sprocket, so I doubt it's worth repairing. Get quotes for this scenario to help you decide. I think @Crasher may be near or in Nottingham, and might be prepared to give you a ballpark idea.

It is belt driven, but as above, you can't see it without removing covers, see toothed belt; toothed belt guard - Octavia(OCT) [EUROPA 2013 year] (7zap.com)

Only if registered, which is $99 to do. See function chart here http://wiki.ross-tech.com/wiki/index.php/Functions

You can't run the engine with timing cover off, so that aspect of mechanic's plan can't work, I think. And it's hours of work to get it off and on again.

Finish the diagnostics with TDC check before making any assumptions. Chain timing on the HTP engines.

May have happened as you started to crank it over after the hill park-up. Unfortunately the design of the chain tensioner is such that if the engine is rotated backwards, oil can be squeezed out of it, meaning there isn't enough push on the chain guide to ensure that the chain stays engaged on the sprockets.

Good start, but you would also ideally take spark plugs out, rotate engine in running direction until no.1 piston is as high as it can go, then check slots in cams are also now parallel to headgasket, to rule out a a chain jump just on the crankshaft sprocket.

Diagnostic readout will not be as useful as a visual check in this case.

I would suggest that you, or someone on your behalf, checks the cam timing. There are two removable covers at the gearbox end of the camshafts. When removed, these give visibility of some slot features on the ends of the camshafts. They should be parallel to one another, and when cylinder no.1 is at TDC, parallel to the head/block joint. Any departure from this indicates that the timing chain has jumped.

Is it a single cam 60 horsepower 3-cylinder or twin cam 70bhp?