Are you sure it was coolant spilling out? Maybe it has been overflowing for a bit and some of it sprayed onto the throttle body causing it to get sticky.
There is a handy OBDI reference on the site here
http://www.cadillacforums.com/forums...x-engines.html (OBD I codes for 4.x Engines). E26 and E27 both point to the throttle switch, which is an ON-OFF sensor inside the Idle Speed Controller assembly. E48 points to EGR valve. Either the top of the engine got coated with coolant or it's been let go.