I searched lemon and found loads of info on this issue! Lol
Found out it's lemon juice (on it's own or with a mix of bicarbonate of soda) you soke them in.
Also seen nic replying to pretty much the same question from 2010. U must have the patience of a saint! Lol- sorry, untill I searched lemon not a lot came up.
Also people tend to say eBay sensors don't do a lot where as the Toyota parts make a noticeable difference.
It's now done 90k miles, so prob wouldn't hurt to replace them. I think I was wrong about one sensor reading the air intake temp, am I right in thinking one is before the cat and one after on the Uk TT? Lemon juice test may tell me if it's time to change them as I understand it's a temp fix.
Just hope Its straight forward to remove them- don't want to snap anything! :0