Anyone know what year they stopped using the knock sensor on the XJ 4.0? A buddy of mine thinks he has lifter noise, but it only happens at power, and it is nice and quiet at idle. I think the lifters are fine; I haven't gotten in to it the diagnostic far enough yet, to say what is making the noise we are hearing, but I did notice that Napa didnÆt have a knock sensor listed for my '99 XJ, but they do have one listed for his '96 XJ, which brings me to my original question of when it was removed from the 4.0, why? I would assume something is programmed into the computer to compensate for it?

Thanks,

Sean