oh no its broken.... oh no its not!

On the way home tonight.......
Gave the car beans , TC off , splashed through a very small puddle (enough to barey be noticeable , about 3 in deep)

I was about 1 minute away from home, pulled up on drive.......

Car idleing between 1200 and 1500 rpm , going up to 1500 and dropping back.
Consistently well over the normal idle speed.

Now I struggle to believe its water in the electrics , although it is very wet round here at the moment.

Anyone got any ideas?
Have I even got a DV failure?

Went out earlier and car is still not right , varied high idle , and on and off the throttle it just doesnt feel right!!!

Im so sad , its only just run it , 1400 miles

which a quick check under the bonnet reveals......

the fecking oil cap is unscrewed
screwed back in and oil check its back to normal

BUT I have absolutely no idea how it managed to come undone!!

Anyway if it happens again we all know what it is now

normal thrashing to resume , panic over........