blaucha58

Hi guys, the Service Engine Soon light came on in my 1998 Maxima, and sometimes its solid but sometimes it flashes (typically when accelerating, but not always). I took it to autozone to read the codes and i read for a cylinder 2 misfire and a bad knock sensor. To try and fix the misfire, i replaced all of the spark plugs, while performance is now better than it was when the problem started, it still isnt as good as it used to be, and the SES light is still on and sometimes flashing. I'm going to replace the knock sensor this weekend, but since the light is still on i assume that means the engine is still misfiring. Could it be the knock sensor causing this? What should I do next? (trying to avoid paying Nissan $100 for a diagnosis).
btw, ever since the problem began, my mileage has dropped from about 25 mpg to 17ish mpg.

ABIGBRAIN

iTrader: (1)

Did my KS this evening just before sundown. 12 mil socket and 3/8 rachet was all I needed to take out the old one. small flathead to remove clip and I was ready to install the new one.

Total time: less than 20 minutes
Total cost: $10 and change for EBAY KS
Results after ECU reset: No more KS code and more power at part throttle while engine is fully warm. (Before I had gobs of grunt while it was cold that only lasted until the engine warmed up)

Next on my list is Front/Right O2 and Rear O2 sensors. EGR tube cleaning will have to wait until spring.

JimmyRooney

Great thread, and awesome advice from everyone!! I'll be tackling this in a couple of weeks on my '97 SE!!

SPER

I'm glad that I've helped so many people with this tutorial.

I'm going to be changing my KS again.. Last week my car overheated and died on me, I was hearing a lot of knock in the engine and it was very rough. I know that everyone says the KS won't cause the engine to stall.. But I'm going to try and be optimistic and hope that replacing the KS will at least allow me to drive to my mechanic and get it checked out more thoroughly..

SPER

No thats not a toy, its a melted knock sensor. I feel so bad for my car for letting it overheat like that. I used a rachet this time, I had the the old one off and the new one on in literally less than 10 min. And I only got about 5 cuts on my hands and opposed to the 15+ the first time I did it.


My Maxi started and I drove it around the parking lot but I'm getting a chirping/squeaking sound from the engine, also some white smoke from the back of the engine and smoke out of the exhaust. I'm going to make a separate thread for all of this, wish me luck. And goodluck to others changing their KS's.

queenambeach

iTrader: (3)

Great write up....I tried again a second time and was finally able to change my KS.....my hand was pretty badly bruised and cut up, but the savings was well worth it.

Thor West

I just finished reading almost all of the 240 messages about changing the knock sensor. From what I read I'm not sure ( hell, I don't have a clue), what my '95's problem is. I had a light, read a KS trouble code only, and started reading about knock sensors. Then the trouble light extinguished and I've been driving it about two weeks without another trouble light. But!
For about a year my easy starting smooth running little beauty has been hard starting on the first start of the day and surging when climbing slight grades at rpms below about 2000. A local radio car guru suggested injector problems. Agressive use of my right foot causes normal great perforrmance
Have any of you seen similar problems?

steezmuffin686

inspect plugs..

2brosgixxer

Check your codes again even if the light is off. Sometimes a bad KS will not trigger the light to come on. Double check and make sure the code is not still "sitting in the background". You can check the codes yourself by using the screw on the ECU to the right of the gas pedal...don't know how, here you go. http://vbxmaxima.8m.com/ecu.html KS can be had on ebay for about $10...heres a link to the one i bought and installed a few months ago http://www.ebay.com/itm/NISSAN-KA24D...abf694&vxp=mtr

prozak

When I do a knock sensor, and I've done many, I use the following

1/4 inch ratchet (fine tooth preferred)
Super Long (at least twelve inch) extension
1/4 inch universal swivel
Swivel 12mm socket
Expendable magnet, preferably one that you can change the angle on. Try not to have too strong a magnet.

Basically the steps are all the same, you can either bend the bracket back a little to get your hand in there, but if you've got fat hands like myself that may not work and isn't really rexommended. Use the magnet to grab the bolt after you get it loose and it falls down in the intake valley.
Remove the sensor from the harness CAREFULLY. It definitely helps to have another harness connector if you're ever at the junkyard. Mine disintegrated when I attempted to pull the safety clip from the connector. Luckily I grabbed my KS with the connector!

As far as replacing it goes, much the same as all the other info states. I personally put the bolt back in the sensor and used the magnet to weasel the sensor back onto the bolt hole, got it to catch a thread, and then forced the magnet off.

Another good thing to do, especially with any resistance spec part....test it with a meter before you use it. I got a lot of faulty parts when working for Pep Boys, so I got into the routine of doing so.

Kansas Storm

I just did this job on a 1998 Maxima over the weekend and was able to use a 1/4 in drive 12mm socket with a swivel and long extension to break it loose. I tried the wrench thing and did not suceed, so I changed the plan of attach. I did have to cram my hand in the small opening and the cuts and scratches are healing nicely. Thanks for all the info, it was spot on. Car now runs great after a new $8.00 part from ebay.

dwapenyi

iTrader: (3)

Assuming you've done all regular maintenance, how about cleaning your throttle body? When I did mine low rpm drivability and smoothness improved greatly.

Also, A bad knock sensor will not cause any drivabiltiy issues. It will just dial back the performance of the car a little. I bought my car with a bad KS and drove it from LA to NY. No issues. In fact it's still there right now. Of course I'm going to replace it but I'm waiting to do my 00VI/valve cover gaskets/KS/EGR/IACV all at once. Complete upper intake overhaul



DW

carsnwomen91

socket method
http://www.youtube.com/watch?v=R2ntaxi7bXk

wratchet wrench
http://www.youtube.com/watch?v=fPIMO...hannel&list=UL

this dude does a lot of maintenance videos on the 4th gen, check his vids good ressources

goliath

Just replaced my KS on my 96 max yesterday. getting it out was easy. I removed the air cleaner all the way to the manifold to make it easier to see things. Remove the green connector. it gives you more room.

I cut the bottom straight wire part on a metal coat hangar at either end. I electrical taped the sensor connected to the harness to one end of the cut coat hangar and taped the harness about 4 inches up as well. this prevents the sensor from spinning on the coat hangar. bend the lower part of the coat hangar so that when you insert the hangar it positions the sensor parallel with the bolt hole. You'll see once you try it. Once positioned on the bolt hole, sneak your swivel and extension over the bolt and carefully turn the bolt until it catches. took about 10 minutes. worked like a champ and no deep gashes trying to get my fat hands in the access area.

LadyMaxLuvr

Any one have any more suggestions for getting this sensor in? I've tried all of them and no joy after 7 hours.

Getting it out was easy! 5 minutes. Getting it back in I simply cannot get my hand in there and the coat hanger trick was nice but I can't get the bolt to catch.

mikeg75

Did you try using masking tape? I was nearly in hysterics myself, when I was trying to put mine in a few months ago. Mine was only a couple hour job though. 7 hours and I would have lost it!

I used blue painters tape to hold the knock sensor and bolt in place, and then once positioned, I used two fingers (middle finger and index one on my right hand), to spin the bolt until it caught. Once it caught, I gave thanks to the Lord, and took the masking tape off before using my wrench to tighten it up!

The way I taped the bolt and KS together, I had the bolt loosely taped at the top but sticking up so it would stay in place once I started turning it with my fingers and I also had just a bit of tape on on the bottom of the KS as well.

Give that a try if you haven't already...

floydthedog

great writeup! thank you! damn you big hands!!!!

gladiator

iTrader: (1)

how do I know my 99SE is cali spec?

it doesn't seem like theres as much space as the pictures op posted

dwapenyi

iTrader: (3)

On the 95 maxima, like my 98 I30, you can actually see the knock sensor through that gap as shown in the pictures.

My friend's 99 I30 however, you can't see s$%&^* because of all the emissions stuff in the way. If that's the case with you, then you have a 99 Cali spec maxima. The lower intake manifold is different too because 99 cali have swirl valves whereas 98 and lower don't, and probably 99 Fed Spec.

SPER

Ohh wow, haven't been on this site in a while. I'm glad to see my tutorial is still helping people out and that the pictures are still up after almost 4 years

I'll probably be on here more often, my 98 SE I bought last year has a LOT of work to be done to get it nice.

signals

You can get new in ebay for about $7 shipped from china!

gladiator

iTrader: (1)

crap! I have cali spec 99

wish theres another tutorial on how to take off all that crap blocking the KS!

MrTruth

I wish I have seen your post before. I paid some $$s to the guy to replace it thinking it is not for me.

Your kindness of sharing these pictures will save money for several people who are a bit more confident and take your helpful message post.

thanks a lot for your kindness!

regards

DBear

I have a CA 96, so I assume we have the same crap, although there might be a swirl valve on yours that I don't have. The tricky part is the sensor, because it's held in place with a 10mm nut on the bottom. To get to that, you need either a flex head wrench, or a crow foot wrench. Crows feet look like this: http://www.sears.com/performance-w35...2&blockType=G2. I just wandered into Sears one day and found a loose one for a couple of bucks. You stick it on the end of a long 3/8" socket extension, then crank it with a socket wrench from above. It comes off easy, but have your magnet-on-a-stick ready, because you WILL drop it at some point.

dwapenyi

iTrader: (3)

Nope, only 99 Cali models.

Mines a 98 Cali and I can see my knock sensor

Amerikaner83

iTrader: (17)

I sorta dread doing this in my 99 FED spec

gladiator

iTrader: (1)

yeah, its almost not visible at all. I will try to include pics tomorrow

SPER

Sorry to hear that, it gives me great satisfaction knowing that I helped a bunch of people not get ripped off. Even if it's just one thread, it does feel good. I don't visit these boards as often as I'd like to, but when I do I like coming to this tutorial and seeing the new posts from people it has helped.

ogomez73

Question, is there a particular knock sensor that I need to buy, a name brand that's better than another generic knock sensor? should I look for the price or make of the knock sensor company, I saw one on Amazon for about 7 dollars.

gladiator

iTrader: (1)

thats probably the same as ebay ones, which were proven to be good on the forums

ShocknAwe

iTrader: (3)

NTK if you cant get OEM

ABIGBRAIN

iTrader: (1)

I couldn't get to mine either with the tools I have so I pulled the KS and sub harness off of my then recently totalled 95 and relocated it on my 99. So far 7 months later, no code and more importantly no "pinging"

Andy

gladiator

iTrader: (1)

where did you relocate it to? I might try that if I can access the harness and pull the wire out

ABIGBRAIN

iTrader: (1)

I will take a pic later today and post it up.

ABIGBRAIN

iTrader: (1)

On the front of the intake manifold, KS sub-harness is in the yellow sleeve.

ChrisMan287

iTrader: (34)

You might as well have put a resistor in it

ABIGBRAIN

iTrader: (1)

The KS is fine just the way it is. This is only a temporary solution until I install the 00VI setup this spring. When I have the old manifold off and out of the way I will remove the old KS and install the newer one (pictured) correctly.

Andy

gladiator

iTrader: (1)

how easy was it to remove the harness from the original location then?

ABIGBRAIN

iTrader: (1)

The sub-harness connector unplugs easily as it is located just to the right of the intake manifold ( if standing at the front of your car ). If you plan on relocating the KS you will want another sub-harness as well since the other end of the harness is connected to the KS under the manifold. If you are unable to loosen your original KS, odds are you will not be able to disconnect the sub-harness at that end and a new or junkyard harness will be much easier.

Andy

signals

How did you get the wrench on the bolt head with your left hand? Was it the box end or the open end of the wrench on the bolt? I got with my RH the box end of 12mm wrench on the bolt. Got my hand very carefully out witout disturbing the wrench resting on the engine block. Now I wanted to leverage forward end of the wrench with a long 1ft screw driver. Remember i am not holding the wrench any more while I am manipulating the the screw driver into postion to push the end of wrench forward. Suddenly the wrench came off the bolt!!! Start all over again? Can you pleaase give your procedure without missing any steps/ details because its a very delicate tricky and iffy method. Also can some one give blow by blow picture of the alternate method as per FSM (factory service manual). FSM steps are very difficult to follow. i guess they write for factory trained tecnician, not for noobies like me. I read earlier some one took the plenum cover off and put back on 30 mts. I wish the guy had described the details of his method! I would adapt too rather than spending hrs, hrs, and hrs getting the hand and tool thro the cave