I have just over 140000 miles on my 1st gen and have the knock sensor code. I have read through many of the posts about it here and thought the general consensus is that the sensors themselves rarely go bad, it's the harness that's the culprit. I am thinking of just replacing the harness and while I'm in there, change the by pass hose and the spark plugs. I bought the vehicle with 106000 miles, so as far as I know these may be the original spark plugs. Maybe they are worn and causing a knock due to poor spark? I have also read that irregularly worn tires could make the sensors go off? That seems unlikely to me, but mine are worn and I was going to be replacing them soon. So has anyone just replaced the harness with success? Most say this is a difficult job, I usually work on everything myself or with a mechanic buddy and from watching a few videos and looking at the vehicle it really doesn't seem like that big of a nightmare to do. Not that I want to be overconfident and then get my butt kicked! It's going to be a couple weeks before I can get the parts and time to do this,thankfully I have a truck to drive in the meantime, plus the engine light comes on after about 5 miles of driving after I reset it!