Breezy_Pete

Did you fix the exhaust leak at the flexi? Expect the new sensor to sit at about 0.45V, as per this official info:

Fingers crossed here, please let us know either way though.

I get a bit less than 10 miles per litre, approx 42mpg, but my driving pattern is almost all short 5 mile journeys.

See correction/edit to previous post. I was looking at the wrong log. I think yours should probably sit at around 0.45V like my Polo, so you're probably right.

Maybe. It's a wideband sensor, so they tend to stay at a constant voltage when in closed loop operation. My BKY engined 2005 Polo sits at 1.5V, what's the engine code of your car? Correction, our Fabia 1.2 sits at that voltage, the Polo maintains approx 0.45V.

Fused at 15 Amps I think, so not much more than that.

The circuit is very simple. Light switch to fuse 65, then to bulbs and telltale input to clocks. With lights on and switch pulled out one click (or two) check for 12V at both ends of the fuse 65 slot. If you have power at neither it's the switch, if you do have 12V there, it's the fuse or the wiring onward towards lights. Haven't had the front bumper off recently and forgotten to plug them back in again when refitting?

Fuse 17 if the car has start/stop system, fuse 50 if it doesn't.

The alarm horn is under the car, just under the front left of where the rear bench 'rise' is. Under a steel cover with some awkwardish screws. If you lift the rear seat bases you can see where the wiring goes through to it Edit, we'll that's where I found it on my Polo.

There's another power feed to Central Convenience on fuse 49, so I suspect that fuse 60 removal won't cause anything other than alarm deadening.

What's the tenth character of VIN?, that's the model year which gets us even closer. Will check some diagrams now.

What year is the car? On the first diagram I looked at, the same fuse goes to interior monitoring sensor and central convenience module. Latter might be disrupted undesirably. Could try just pulling fuse 60 and seeing if anything else doesn't work, but happy to look for correct circuit if given year. Funnily enough I removed the alarm horn from my Polo just a couple of weekends back, pre-emptively rather than 'cos it was causing trouble. Had Lithium rechargeables inside rather than NiCds or similar.

Check that your brake lights all work first. Then if they're all OK, check the brake servo vacuum hose at the joints with the non-return valve. Look and feel for splits all around the hard plastic section where it stretches over the hose barbs.

Picture with approx dimensions here. You need a riveter capable of taking the rather large size, ideally the 'lazy-tongs' design or a pneumatic one. As you're maybe not far away I could possibly lend you tool and spare rivets, if you could put down a suitable deposit? I'm near Abingdon.

I expect all that is exactly as it was when it left the factory.

Very likely to be that, yes, but it should stop smelling of petrol very soon after a cold start.

I seem to remember this situation being discussed before, but can't remember the resolution, or even if there was one. Is either valve a genuine Skoda one or a genuine Pierburg one (generally same thing)?

Can you do 'output tests' on the engine ECU and see if you hear the valve clicking at the appropriate point in the sequence?

Bodge it and scarper. Worth checking behind the wheel arch liner at nearside rear, as you get a much better view of the back box with that removed; you might find a bigger hole there. Does it sound farty?

I doubt it.

Check further back too, a leak after the cats is not going to affect engine management but will affect the tailpipe lambda measurement.

Don't know, but sounds unlikely. If you have VCDS why not do the basic setting?

Ask the MOT place for another copy, or just what the exact lambda number was. They must have the info.

Please post a photo of the emissions fail printout, with the lambda, CO, and HC numbers. Exhaust leak seems quite likely to me, especially if lambda number is high.

Around 20-30mA, 0.02-0.03A I would expect, if all is well and everything is properly 'asleep'. Slightly tricky to both get the car into that state and measure the current without re-awakening it. There's a method I've described here that works, but it will be easier with two people as it's really a three-handed job: https://www.briskoda.net/forums/topic/495243-quick-and-dirty-parasitic-current-measurement/ Keeping the red meter probe 100% connected to the battery clamp while lifting it is the tricky bit, which a 2nd person could readily assist with.