PetrolDave

Have you asked in the Octavia Mk4 forum? The Mk3 and Mk4 have quite deiferent electronics.

What features do you want to enable, some need a FeC code not just a software update.

Cost and availability at the time of production - even Audi do this, it's not a "Skoda thing".

USB Aux or 3.5mm audio only Aux?

You'll get far better (any?) response by posting in English - which is the official language of this forum.

They're all shown as intermittent which means the faults weren't present when the scan was done but were historical.

But if ODIS says there's no updates then the dealer will say it's up-to-date even if the car has known issues (like the climatronic sync issue you mention). This is what puts me off moving to a Mk4 - getting the firmware (and in a few cases on older Mk4's hardware) on several modules updated isn't as simple as it should be because Skoda don't acknowledge all the issues.

IIRC this was mentioned on here a few years ago as happening when the tank is about 3/4 full due to there not being any/enough baffles in the tank.

Check for binding brakes or failing bearing on front right wheel.

Based on my several times a day browsing the Octavia 3 and 4 forums, personally I'd look for a FL Mark 3 first.

Leave the key in the ignition and don't open the door?

With VCDS it shows modules that are SFD locked when you do a scan, I don't use OBDeleven so can't comment on whether that indicates SFD locked modules in a scan.

OBDeleven or VCDS, provided the airbag module isn't SFD locked.

On any Skoda with a Battery Management System you must always connect the negative lead of an external charger to the chassis NOT the battery negative terminal. If you connect it to the battery negative terminal the Battery Management System won't know the battery has been charged.

15 reg means it's an Octavia 3, so please post in the Octavia 3 forum where fellow owners can offer good advice.

It's the most common place for car manufacturers to mount tweeters, as high frequency sound is very directional and they don't want it to get absorbed by legs/clothing/etc. plus the theory is that if the sound appears to come from the windscreen then a drowsy driver is more likely to stay looking ahead rather than down.

Especially in countries that still generate a lot of their electricity by burning fossil fuels, most notably China which consumes over 50% of world coal. Coal Consumption by Country

Do you mean ECU? When you titled this thread ICU I assumed you meant some kind of reference to getting your Yeti working again without needing to go to the car equivalent of an Intensive Care Unit! The ECU and instruments will need matching to the new keys, which isn't a job that normal diagnostic software can do, it usually needs a dealer-level piece of software such as ODIS.

Lithium does not fall into the accepted definition of a "rare earth" element Rare Earth elements but the elements used to make the fixed magnets in the electric motors "stronger" most definitely do fall within the accepted definition, most notably Neodymium, Praseodymium and Samarium.

I had, it seems wrong, assumed that the switched feed was positive? However, that fault code could also mean that the power feed to the injectors is intermittent.

As ApertureS says you need to go to a garage that knows what they are doing, I've always found that independent Skoda/VAG specialists have far more product knowledge than the majority of dealers, and there's no way a 2011 Yeti is beyond economical repair!

Without a recognised key the immobiliser won't be unlocked and the ECU functions will be enabled, so at best the engine will fire for a few seconds and then stop -so it will IMHO be a waste of time and effort.

Won't do you a lot of good - the ECU controls whether the electrical fuel pump runs, the injector timing and amount (no mechanical injection pump here), the position of the actual throttle valve in the intake (yes modern diesels do have a "throttle" valve and there's no physical connection between the pedal and the valve). So yes you can hot wire the ignition on, but the engine cannot run without the fuel pump running, fuel being injected or with an intake with the throttle valve stuck in the idle position.

Even when brand new a car with a 150bhp engine won't have produced much more than 110bhp at the wheels, since power is quoted as measured on an engine dynamometer not a vehicle dynamometer so you need to take account of the 25% average transmission losses. So 80-90bhp is only a 20% loss over the years. Shows how little knowledge most people have of how ICE vehicles are specified.

Have you looked at and tested the connection where the injector wiring connects to the chassis - I'm thinking looseness or corrosion?