Ok,

So over the past 3 weeks I've had two knock sensor warnings trip. The first time I didn't know what caused it as I was on the way to work. So I reset it and waited for it to happen again. Sure enough, I've figured out the conditions for it to trip.

When leaving my house, there is a steep hill that I have to climb...so my engine isn't fully up to operating temp. Now the past couple of weeks, I've been taking it easy..only climbing the hill at around 25-30 mph. Today, I was climbing harder at around 35 mph instead and the light triggered about 3/4th up the hill. This was exactly the same conditions that it tripped the first time (going up that hill at high load). So now my question...

Is this the knock sensor going? or something else? My area is known for not having the best gas available even when I buy premium (only 91 oct here). I'm scheduling to do an oil flush, sump o-rings/gaskets, and trans flush this weekend. Mostly because it's time and I have a ticking lifter so I'm trying to remedy that. However, I'm looking for some BB opinions on what to do before I go to the mechanic. I can keep going up the hill more slowly, but I don't think that's a permanent solution, this area is very hilly.