I just changed my KS and now want to make sure this thread is more thourough and informative than the majority of Knock Sensor replacement threads. I found the information necessary to do the install on the Org but found individual accounts vague. So rather than read everyone's reply to the subject, I offer you my account of removing and replacing a Knock Sensor on a 1997 Infiniti I30 (same as a Max, so don't hate)

For tools I used a 3/8" ratchet, with a 6" extension (or equivalent), a universal joint, and a 12mm socket. Also used my hand, so depending on your situation you might benefit from having someone around with very small hands.

First, whenever working with anything electrical, disconnect the negative battery terminal and protect it from metal contact by covering with a DRY towel.

Ok, now observe your target. The KS sits in the V of the engine block and you're going to have to get to it underneath the UIM from the driver's side. On a 95, this is little or no sweat. On the 97+ there is some sort of green vacuum (EVAP???) sensor blocking the already restricted orifice. Do not remove any of the intake assembly as it will not grant you more room to work in this case. If one could remove the sensor, everything would be self-explanatory, but the retaining bolt is blindly positioned underneath with no reasonable way to get to it, so I recommend to just UNPLUG the sensor (dont forget to PLUG IT BACK IN!). Unplugging the sensor makes life a lot easier.

Ok, the KS is held in place but a single 12mm head retaining bolt, and to make sure I was fully seated on the bolt, I needed a flashlight in broad day. I also noticed, after I made contact with my joint+socket assembly, that unless I held the joint+socket assembly as straight as possible (ratchet pressing against UIM) the angle was not sufficient to transfer the necessary torque to loosen or re-tighten the bolt. A second u-joint might have made things easier, but I didn't own one, so not sure. Once you loosen the bolt all the way, the old KS should come out with the bolt through it. Getting it out should be the easy part. You should take this time to swab out any visible rust or dirt from the old sensor's contact point.

Now that you have the KS out of the block, you need to remove it from the wiring harness connector. There is a thin piece of metal acting as a retaining pin for the sensor, you must remove it prior to removing the sensor from the harness, otherwise you will damamge your harness or connector and will be a *******. I lost mine while gently prying it off with a small standard head screwdriver, but fashioned an exact replica out of a paperclip with a pair of needlenose pliers in under a minute. Whatever you do, dont replace the sensor without installing the pin back in place, otherwise it could come loose and you could get a bad connection while on the road.

Now you should have a new KS on a new (or re-used) wiring harness, ready to go back in. This is a bit tricky. At first I tried, and could not for the life of me get my hand into that cramped space, so I put a little RTV (only glue-like substance in my trunk) on my 12mm socket and lightly glued the retaining bolt in so it would not slip out. I then manually guided the KS onto its pedestal mount and tried to slip the bolt back in overhead. I struggled for a couple minutes and then suddenly, without thought, slipped my left hand down under the UIM and was able to hand-tighten the bolt with the sensor in the correct position (not contacting the UIM). Once I had a few threads going I went back in with my joint+socket assembly and finished it off. Remember torque spec for this job is 8-15 ft-lbs, so that means tighten it til it doesnt want to go anymore but DO NOT FORCE IT, otherwise you will crack your new KS and be a *******. For the finishing touches, reconnect anything you disconnected and give your ECU a reset.

Thats pretty much it. It you stayed cool and collected you should be done, start to finish in 20 minutes. Enjoy your renewed power, its better than fuel injector cleaner!

 

Great post - gonna be useful in a couple of weeks for me.. Thanks!

 

OK it took you 20 min. from beginning to end. LMFAO! BS! but whatever. How many hours, days or months did you fish through the KS threads. You already said you did. Dude you are ***** out lying and that KS put you through hell just like it did everyone else.

 

Before I started taking the IM off, it would take 15 mins tops.

 

I have heard of plenty of people on the org swap a new KS in about 20 mins or so. It really is not that hard of a thing to do.

 

Listen buddy, this is a place for owners of the Maxima and I30 to share experiences pertaining to our vehicles and information on DIY maintenance, and you're not contributing either. So .

 

Jerry, Jerry, Jerry!

 

sandy, meet vagina...

 

It took me about 30 mins at night with a s***** flashlight to change my KS. Do hate, elaborate.

 

Using a univ socket requires that things be set up just right. I think a lot of folks who attempt it and fail miss something.

I also did mine in 30min, and it would have been 20 if I had thought of the RTV trick. I did a similar thing with a small strip of duct tape. I like the RTV much better.

Dave