Thanks to JimV and DGeesaman!!!

1) Don't bother with the chiltons/haynes/nissan manuals for this job. They all suggest removing the whole manifold to do it. Not necessary. Although it sits way inside the manifold, you can get to it without jamming your hand in and making a bloody pulp, and without removing that works. 2) Buy a 12mm flex-head socket and a 1/4" drive 14" extension Also be sure to have a telescoping magnet pick-up tool handy and a long (long!) set of needle-nose pliers. While you're at it, I suggest picking up the 10mm flex-head socket too - I use it frequently. 3) Using this 12mm + 14" extension, you should be able to access the bolt holding down the knock sensor. Getting it to crack loose might take a little torque, and if it won't budge just rotate the socket a face and try again (flex heads apply varying torque depending on which angle it's bent at). Once you crack the bolt loose, get it out with the socket, magnet, or pliers, whatever. Lift out the old knock sensor by its harness. 4) Take a piece of duct tape about 1/4" x 1". Wrap it around 2 sides of the bolt head, and insert it into the flex socket with the rest of the tape hanging out. Now wrap that tape onto the socket so that the bolt is a) snug fit in the socket but b) the tape won't simply fall off. Make sure that the tape won't get caught under the head when you tighten it down. Using the harness to position the sensor, put the bolt in and carefully using the extension/socket to thread it into the hole. Snug it down but don't overtighten. Just a little snug is all. Now remove the socket, and the tape should be hanging up enough that you can now use the pliers to carefully peel it off. 5) Reset ECU. Done.

Dave

Thank you Dave! I'll go see if I can locate the thing in there.

HM