Knock sensor problem

[Spanky]

Need some help here please. The following fault code appeared the other day and comes back within a few minutes if I clear it:

16716 - Knock Sensor 2 (G66): Signal too low
P0332 - 35 - 00

Can someone confirm exactly where the two knock sensors are located on the 2.7T and which one is number 2? I'd like to check the connector to make sure it's not loose before investing in a new sensor.

I STFA but couldn't find anything. Can anyone point me in the right direction? Thx!

[Spanky]

Ok, I figured it out. For information in case any of you encounter the same problem in the future, if you're standing in front of the car then knock sensor 1 (G61) is on the left (passenger) side and knock sensor 2 (G66) is on the right side.

Both knock sensors are under the intake manifold, one on either side, and not easy to reach. It's definitely possible to remove/replace #2 without taking off the manifold, it just takes a bit of time and patience. All you need to do is remove the Y-pipe and you have access. #1 on the other hand would be a real biatch by comparison and I suspect the manifold would have to come off. It's buried somewhere under the part of the spider hose that connects to the f-hose.

The part number for #2 is 078 905 377, at least on my '99 S4. It has a brown connector. I have no idea for #1 because I didn't take if off. It also has a brown connector so I guess it's the same.

I understand that the mounting torque is critical for correct operation. Would anyone with a Bentley manual be willing to confirm the correct torque please? I think it's 20Nm but want to be absolutely sure.

[CONTROL ONE]

How did you determine it needed to be replaced? Did it fix the problem?

[Spanky]

Nothing special, once I'd figured out where the sensor is I just checked the connector to make sure it wasn't loose and there was no corrosion of the terminals or anything. Everything looked ok so at that point I just assumed that the sensor must have died. The car's nine years old after all and things keep breaking on a regular basis, lol.

I'm sure there's an accurate way of testing the connector etc... but the new part is relatively cheap ($35) so I thought I might as well go ahead and replace it.

I've taken the old sensor off but I haven't fitted the new one yet. I'll make some time this weekend to sort it out.

Oh, I found a Bentley manual for download via this forum (thx a million to the person that posted the link) and the exact tightening torque for correct operation of the knock sensor is 20Nm (15 ft lb).