I have the 5.4 V8, on mine the A/C outlet dripped down onto one of the passenger side O2 sensors. I don't know which one its called. Turn on your A/C, look for where it drips down and change the O2 sensor right below the drainage. The remedy is to get a PCV elbow and some tubing. Put the elbow into the drain hole in the firewall and attach the tubing to re-direct the drainage. It sounds easier than it is due to little to no room to get your hand up where it needs to be. Mine has been straight ever since. P.S. Wait for engine to cool COMPLETELY, your hand will touch the block to complete the task.