My car has 68k miles on it. It had a front end collision and was salvaged. I had to take everything off the front in order to repair it. (This is when I bought the car, after the impact) Then when I started driving it and the knock sensor came on. Cleared the code, and it came back almost right away. I have cleared it probably 5 times. I have done quite a little bit of research on the knock sensor problem and I have tried what seems to be about everything.

What I've done:
1) Replaced knock sensor
2) Tried Octane 104 Booster
3) Tried a bottle of seafoam engine treatment
4) Replaced spark plugs (NGK IRIDIUM)
5) Replaced Ignition coil (MSD)
6) Replaced Ignition wires (MSD)
7) Tried gas from other stations
8) Tried following the wire back into the engine (it doesn't appear to be severed from the front impact)

I have been listening closely to my engine, and there appears to be a slight clicking not anywhere near as extreme as the"DEATH RATTLE" but still audible. I am going to try replacing my timing chain tensioner this week and I am also going to try replacing my throttle body and see if that somehow is causing the problem.

So I was wondering if anyone else has had this mind boggling issue and if they could please help me!
Thanks

 

Please do report back what you find out. I am having a similar problem. I haven't tried all the your solutions (except for new NGK plugs). Will be replacing the spark plug wires next, but don't expect the noise to go away since it didn't for you.

Please report back how the throttle body/timing chain project goes...best of luck!

 

I think I may have found the solution without having to change the throttle body and the timing chain tensioner. I was looking at the plug on the car side of the knock sensor and it looks as though my wires are half way back into the plug. I took the rubber boot off and it turns out that they have become completely undone. Apparently when the car was wrecked the wires were pulled out of the pug a little bit and it broke the clips on the terminal. I am going to the Mini dealership tomorrow to buy the plug and terminals. I will let you know as soon as I try this if it resolves my problem.

On the bright side of things, I have a bunch of new sensors and stuff that I hopefully won't have to worry about changing for a while