[freemansteve]

It does look as if it pokes into the exhaust stream, so maybe a lambda ? But it could be one the two coolant sensors, as I believe water circulates around the internal manifold.....
I'm surprised that it's not hot enough around there to keep it dry....

For the cam sensors, online stores only seem to report one part - it's makes sense that they are the same parts, but I'm not certain. Seems odd to have two cam sensors though (useful info if your cambelt has snapped though! )

 

[Stuart Hudman]

@freemansteve - 99% I reckon you are right - check this out VW Up!, Skoda Citigo, Seat Mii 1.0 MPI engine coolant temperature sensor location - YouTube
Also...adds up, as it had water in, so maybe this is "faulty" and leaking into the plug.

 

[freemansteve]

I think you've nailed it with that!
Here's a theory -

• water temp sensor leaks, maybe causes inaccurate data, but not out enough to trigger OBD fault code.
• ECU thinks engine is colder (or hotter) than it actually is, maybe enough to make it alter fuelling or timing, which has a downstream effect that triggers knock sensor error....?

I'd replace that leaky sensor either way, and see what happens !

It does leave me curious about the location of the pre-cat lambda....

 

[Stuart Hudman]

Well...only if I could get the darn thing out. The bolt came out easy.....but the sensor, although rotates freely will not come out of the block, not even by 1mm to get some leverage behind it. Looking at the new one, there is nothing really to retain it, other than a small rubber o-ring. Any ideas on how to get it out ?