[CREWZIN]

Jonathan,

Are you sure it isn't the condensation that builds up when the air is on and it's dropping onto the hot exhaust? That would cause the hissing and popping and cause steam to rise off the hot exhaust. The condensation overflow tube is supposed to catch the water and divert it harmlessly onto the pavement/floor near the passenger front wheel but if the tube is damaged or come loose, the water could drip on a part of the hot exhaust.

The dealer will charge you at least an hour's labor ($95 ??) to find it. If you can, get under the car on the passenger side and look for that rubber black overflow tube and see if you can trace it back to source to see it it's loose or torn.