IMO - Before changing the wires or the knock sensor you might try a bottle of Techron Concentrate fuel system cleaner. I throw in a bottle 2 or 3 times a year as part of my normal maintenance program, or if I happen to hear unusual pinging or knocking. Great stuff! Bet it will kill your pinging! Try 2 in a row if necessary. They are only $6 in my area.

My car runs fine on 87 octane. In addition, I have never needed to replace a fuel injector on this car (253K) or my VW (281K). I credit this to using Techron regularly....

BTW - If you try it, make sure you get the "Techron Concentrate", not the regular techron.

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90 244DL 253K - original engine/drivetrain :)