[jruss1601]

I have a 2000 Frontier with a 4 cyl engine. I've searched the stickeys for this topic and it appears as if other members avoid the knock sensor at all costs. The Haynes manual doesnt describe 4 cyl knock sensor removal and youtube doesn't give much information for the 4 cyl. Well, i'm past avoiding changing the sensor. I have removed the current sensor. My problem now is trying to install the new one.

The video i had found on youtube described removing the alternator and the oil filter (which I had done, but didnt give me as much access as i had hoped or needed). A thread i found discussing the topic on a sentra relayed reaching it from under the car. That doesn't seem to be an option with the frontier. So it looks like i'll have to remove the throttle body. During my searching on this site someone also said the plenum must be removed. Does it need to be removed? If its removed, do the fuel lines need to be deprssured or anything like that? To me it appears as if either the plenum or the throttle body could possibly be removed to allow access to the knock sensor.

Has anyone performed this task on a 4cyl that could give advice as to how they've done it and also what they recommend be removed? Thank you for your help!

Also, what is that sensor bolted directly over the knock sensor access. Is it related to fuel or air?

 

[Roader]

I couldn't open your pic and the FSM is no help but this page has a good pic. That thing's really buried way up underneath the intake manifold.

Nissan frontier knock sensor replacement

 

[jruss1601]

Thanks for that. Yeah, i've found that video which led me to remove the alternator and the oil filter, but i still hadnt had much room and i was looking for an accepted method from the members in this forum (whether its this method or another). It sounded like it was removal of the throttle body. If i remove more around the oil filter and alternator then maybe i'll have enough room to install the new KS. I'll give it a try and see if it works.

 

[Roader]

It looks like the guy who did the video went one more step after removing the alternator and oil filter by removing the PVC body. I sure would replace that PVC filter while I was in there.

 

[jruss1601]

It looks like the guy who did the video went one more step after removing the alternator and oil filter by removing the PVC body. I sure would replace that PVC filter while I was in there.

Thanks. I did see that, but i was a little leery of removing pieces i'm not entirely sure what purpose they serve. Since its the PCV body, i feel better removing it. That was my issue in the first post with the contraption bolted to the plenum over the access area of the KS. That was in the picture that won't load. :frown: I'm still not sure what it is.

But you say the PCV filter. You mean the PCV valve right? I can't locate a filter on rockauto or autozone sites. I'm with you and while i'm there and have it apart i'll do everything i can to keep the frontier running like a champ!

 

[Roader]

But you say the PCV filter. You mean the PCV valve right?

Yes, of course. I misspoke.

 

[jruss1601]

I've removed the PCV body and i was able to squeeze my hand in the area to reach the screw and hand tighten the new KS in place. However, i have smaller hands and i'm not sure this procedure would work for guys with large hands since the area was still very tight. So i have yet to take the truck for a drive but i installed everything else and started it up. It appears as if everything worked!

I still wonder if removal of the throttle body is the preferred removal and installation procedure of the knock sensor on a 4cyl frontier.

But everything seemed to work as it should with this method so I thank you all for your help.

 

[Roader]

I still wonder if removal of the throttle body is the preferred removal and installation procedure of the knock sensor on a 4cyl frontier.

Taking off the throttle body wouldn't gain you any room. Taking off intake manifold would, but that would be a whole lot of work:

 

[TDeang]

I followed the video for the most part. I never pulled my oil filter and was able to access the knock sensor through the wheel well reaching up inside the the engine compartment. It wasn't a fun task by any means but it isn't as difficult as it is made out to be.
Pull the belts, remove alternator, remove pcv canister. Practice a little contortionism to unbolt the sensor and install in reverse. Oh yeah, remove the passenger wheel it will make your life a whole lot easier and as always disconnect the battery before doing anything with electrical connections. No one likes an unexpected jolt or sparking a fire.