Battery disconnected . . . . rough idle
 

2000 Boxster 2.7 on 74k . . . . Car going fine then . . . Took out the battery for a couple of days to sort out tatty scuttle area. On reconnection car starts but rough idle, smells rich, misfires and cel on all the time. Drives smooth enough above the idle. Will the ecu relearn settings or is it one of those key in the ignition - leave - start jobs. Hoping it does not need Porsche dealer/indie reset. Anyone had similar issues? Thanks for reading.

Your DME needs to relearn some parameters that were lost when you took the battery out, all this will pass after a short while.

Thanks . . . . Now about that water on the carpet?
 

That's what I hoped to hear :).
Just got to sort out wet carpet, front left footwell. Hoping it was all the blocked drain pipes in the scuttle! Floor feels dry under carpet so maybe drips from the dash area?

If carpets are wet, front or rear drains likely blocked.
Clear ASAP to avoid wetting alarm unit under seat.

Ditto to both comments.

I unhooked the battery to do maintenance. Rough idle.. CEL light.. even sputtered once...after a few cycles all is well again. And I keep those drain holes front and back (I believe 4 holes) clean and check them frequently.

Wet floor-sounds trivial until it floods the electrics under your seat...........
Easy fix -drill a drain hole in the floor.