94 Intrepid Oxygen Sensors

Use the correct socket, don't try to improvise.

Pour Coca-Cola (yes!) on the sensor-to-manifold junction the night before you go to remove it -- the phosphoric acid does a much better job of eating corrosion than any "penetrating oil" available at the retail level. Kroil is even better, but most people don't have any on hand.

Use Mopar, NAPA Echlin, NTK or Standard-Bluestreak sensors, NOT Bosch, unless you want to do it all again (and again, and again) soon.

Yep, oops. Keep a close eye on your gas mileage; odds are excellent it'll start dropping again in a hurry.