I live in Dallas, and in the summer I have to run 93 octane in my 93 245 to keep it from knocking. In the winter when the engine runs a little cooler and the air is more dense, I can get away with 89. The engine does has a knock sensor, but it is not that sophisticated. Still, when mine went bad, it made the car knock even with 93. It's located on the left side of the engine under the intake manifold. Contrary to what you may hear, I don't believe you can test this type of knock sensor by banging on the engine w/ a wrench and observing if the timing changes - you'll need an oscilliscope. So, since they're cheap, and assuming you're running 93, go ahead and change it out. Make sure you torque it down properly, as they're sensitive to the correct torque, which for this is measured in inch-pounds so you'll need a torque wrench that can do inch-pounds.