'96 check engine light

Tonight my check engine light came on. No flashing or anything, just on steady. After the light came on, the gas gauge went to full then back down to what the level should be. I checked all of the fluids and checked the engine for leaks but couldn't find any. After I turned off the car and let it sit in my garage for 15 minutes there was still a ticking or drip noise from the area of the gas tank (NOT the engine compartment). I've never noticed it before but my dad seems to think it is a normal sound as the car cools down.

The light came on after we were in slow traffic (5-10mph stop and go) going around a wreck on the freeway. The temperature gauge remained normal and the light came back on even after letting the car sit off and cool, so I'm not thinking it's coolant or temperature related.

Any ideas?

"...my dad seems to think it is a normal sound as the car cools down"

He's right.

Get the codes that caused the CEL to come on from the computer.