97BlackMax

hey guys, been a while since i've posted here

but anyways, my mom's I30 had it's check engine light come on a couple days ago, and I went outside and decoded it today, and came up with two codes 0707 (rear heated oxygen sensor) and 0304 i think (knock sensor)...now my question is, how much is this going to cost me to get replaced at the dealer? or, how easy would it be to replace on my own? and do you guys know of any way to fix the problem without necessarily replacing it, such as if it needs cleaning or something?

and i remember reading a long time ago about a recall involving 95 maxima O2 sensors, and I was wondering if anyone knew if this applied to the 96 I30s (bought ours in August of 95 the first year it was out)

thanks

KINGMAX

I got my knock sensor today wholesale for $145.70(I work at a dealership), the regular price is 182.13+tx. As far as installing I will do it sunday. The knock sensor is located under the intake manifold and alot of manuals say you have to take the manifold off to replace the knock sensor. Many of the posts I have seen on here though people have managed to replace it without taking the manifold off. I have looked and it is a tight fit but I have small hands so I think it is possiple. Either way I am going to put it in myself. If you don't want to do it call some places and get quotes on what labor will be for that kind of work. As far as the O2 sensor, I think they run in the ballpark of $130 bucks, and require a good bit of elbow grease to get off. If this is the O2 sensor I am thinking about it is located after the CAT on the exhaust. I have access to a lift so it is no problem to get to for me, but even if you can't use a lift you should have no problem getting to it just jacking the back of the car off the ground.

dmk11

I have a '96 Maxima and the same thing happened. The one place I called gave these as a quote (parts & labor):
Knock sensor - $443
Front O2 sensor - $220

Seems very expensive to me. Then again, this place is supposed to be good & honest but higher in price.

What should be a "reasonable" price for parts & labor for both?

Is there a particular reason that might get both of these sensor malfunctioning (maybe the way I drive, etc) ?

Kevin Wong

I went the cheap route. I found a guy on eBay that sells the Knock sensors brand new for $106 shipped. I also bought a set of six brand new ignition coils for $150 shipped...just couldn't pass up the deal. As far as 02 sensors go, foreignpartsplace.com sells the front 2 sensors for $58 each shipped. The rear 02 sensor, I'll buy at autozone for $99. These are all OEM Nissan parts too.

I've also heard that in more cases than not. O2 sensors are still good after replacing them. You would think that they went bad or faulty. But I plan on test the 3 sensors that I'm replacing after cleaning them. Then, I'll know if I can reuse some of them in the future. Suckers are expensive, I'm not going to throw them away if they're potentially still good.

time2reup

Alot of times the knock sensor will piggy back with other codes, so everybody says to replace your 02 sensor, then check and see if you still have the 0304...for those of us that have the knock sensor by itself it is bad and needs to be changed....I haven't done the 02 but the knock sensor is simple if you have small hands and can reach to get it back in....fyi I got my knock sensor shipped from Ken at JerryRome Nissan for 120....he probably won't be able to help you on the O2 but if you need the knock give him a shot...

Jamsan

iTrader: (2)

tell me thats canadian $

Sprint

iTrader: (10)

as someone said before.. knock sensor is just a piggy back code off that rear 02...

replace the rear 02 and you are good to go..

all you need is an open ended wrench and a jack and its that simple.. the front is 22mm .. not sure about the rear.. it takes maybe 10 mins to replace..

Jamsan

iTrader: (2)

dont forget the anti-seize

KINGMAX

Code 0304 is not primarily a piggyback code. I changed my knock sensor last sunday and, well, my car is fixed now. Before I had a loss of power and "bumpy" acceleration. That is all gone now, and my CEL has not come back on. And like the guy said before, it is a fairly simple install if you have small hands. But since this guy is pulling up BOTH codes, I would go ahead and replace the O2 first, clear the ECU, drive it around, and see if code 304 comes back up. When my knock sensor was bad, I reset the ECU and the CEL came back almost immediatly.

Sprint

iTrader: (10)

homey..

why are you arguing with me.. i said 0304 is a piggy back code.. almost every O2 Sensor code is followed by the 0304 code.. i have had it many times.. changing hte 02 sensor the Knock Sensor code dissapears..

Knock Sensor code never appears by itself.. the first step is always to fix the O2 sensors and then if that doesn't solve the problem.. replace the KS

dtholmanmax

I just replaced the rear/downstream O2 sensor on my 98 last week after tearing up the old one trying to get it out of the pipe while putting on my exhaust. I paid 83+tax on that at the dealer. Additionally, I have heard from Joffe that there is a tool you can use to pull 02 sensors out. You can rent it at Autozone for free, just give them a deposit and bring the tool back.

dmk11

no it's not!! a ripoff, don't you think?

Anyways, after reading this forum for more than 6 hours last night, I think I might be able to do it myself.

Since's I'm a girl, I have smaller hands, hopefully that'll help.

I just checked the code and it comes up as 0303 & 0304. I'm going to change the Front Left O2 sensor first then if that doesn't clear the 0304, I'll change the knock sensor too. Thanks for all the advice!

Now, what brand of O2 sensor is OEM? I talked to one mechanic and he said that Bosch is a "lower quality" one, compared to NTK or Denso.. Is this true?

I went to foreignpartsplace like someone suggested and there are 3 different types of o2 sensor. Which one should I get?
Oxygen Sensor OE Connector Bosch $57.92
Oxygen Sensor Denso $80.61
Oxygen Sensor w/ connector NTK Oxygen Sensor by NGK $81.51

What does "OE" mean?

thanks for helping out this newbie.

time2reup

the reason they want so much money to do the knock is because in the manuals it tells you to remove the upper intake plenum...but obviously it's not neccesary to do that. If you do have to replace your knock all you really need is a flex socket and extension, you shouldn't have any problem...check out the skippynet site...it was pretty helpfull, and I think motorvate.ca has a write up as well....

While I have read about 0304 piggy backing I did have the code all by itself, though without a CEL, I just had bad hesitation in the middle of my powerband and bad gas mileage...ran the ecu and got it by itself, so it can be by itself but its seems to be the exception rather than the rule....

Sprint

iTrader: (10)

Bosch makes the Nissan OE (original equipment) 02 Sensor .. however.. i would just buy it from Nissan..

Kevin Wong

OE = original equipment
OEM = orignal equipment manufactuer
OE = OEM...essentially
Bosch is the OE or OEM for our Maxima. I was told by a Nissan tuner that the Maxima and 300ZX are known to have o2 sensors that go out after 5-7 years. Denso does a lot of OE for Toyota and Honda, and NGK also does OE for all Japanese imports. I don't know which one is better than the others. I'm going with Bosch since it's OE and it's what everyone else goes with. I would think NGK and Denso would be better since they are Japanese manufactuers to go with our Japanese engine. Bosch I believe is European.

My continental bias isn't always true however. I've found that german/european made suspension products are superior (koni, bilstein, H&R, Eibach) with the exceptions of Apexi, Tein, and JIC.

Prodeje79

SprintMax is right.
I just had the same issue. My Heat shield on my cat severed my rear 02 wire, then I got both of those codes. I did just install my 02,so as soon as I reset my ECU I will see if the code went away. =)

I am sure it is possible the knock sensor could be bad too, but I might as well save money if I can and make sure its just not the 02.

Good luck

KINGMAX

Whoa Sprint, I am not trying to argue with you. I am just speaking from expierience. Code 0304 did come on by itself in my car(unless you want to count the speed sensor code which has nothing to do with the kcock sensor). I am not B/Sing here, I checked my ECU and I had only those two codes. I changed my knock sensor,reset the ECU, and there are NO more codes(I think my speed senor has a bad connection) and my car, as I said before, drives MUCH MUCH better now it is not in my head. JMAXIMA, helped me do it and we took it for a drive afterwards and he said he hasn't felt my car pull that hard in a long time. You are definatly right on doing the O2 first though, if I was pulling both codes I would replace the O2 first.


P.S. I said 0304 was not PRIMARILY a piggyback code, meaning that I have had it come on byitself(others on this board have too), but yes it also CAN be a piggyback code if you have other problems(such as a bad O2) that could trip the knock sensor code. The KS is like a stethescope for the engine if it detects a knock or ping it retards or advances the timing so the engine can run more smoothly and efficiently.

marcdown20

i have no techinical advice on this matter... but i'm sure both are true

mike

KINGMAX

I can't believe how loud that B-pipe made your car mike

97BlackMax

thanks for all the help guys...i've been out for a few days so I haven't checked this thread, but i read all the replies, and you guys are helpful as always...i'm gonna try to pick up a new o2 sensor at Autozone (you say this is the same as OEM right?) and try and install it myself...i've got fairly small hands and i'll try and get access to a jack

thanks again

Prodeje79

My CEL came back on!

I will have to check and see what codes it is throwing now.

Maybe my knock sensor was bad along with the rear 02 I had to replace.

marcdown20

yes... my car=loud

fst96se

iTrader: (1)

I am posting some pictures and basic instructions on how to replace the knock sensor. I really would like to have had a few pictures to at least show me where the knock sensor was!

The first pic is an open shot of the engine bay. The knock sensor is in that little valley in the middle of the engine that I have circled in red.



The second picture is a closer look at that little valley that houses the crummy knock sensor! You can see in the valley that I have my small craftsman wratchet wrench in there already. I can't remember what size the bolt is.



This third picture is a really close up of the wrench on the knock sensor bolt. If you look close you can see the knock sensor in there inderneath the wrench. You just remove the bolt holding it on.



More pictures to follow!

fst96se

iTrader: (1)

This picture clearly shows what the knock sensor looks like after removing it from its cave! Here it is still attached to the knock sensor harness. There is a metal clip that fastens the knock sensor to the harness. Be sure to remove the clip before you try to separate the sensor from the harness!


Here is the little bugger! To replace the sensor, just reverse these directions!




Oh, here is what your arm will look like when you are done! (minus the hair!!)

time2reup

Its a 12mm bolt, and if you use a long extension and a flex socket its a piece of cake....

dmk11

Can someone post instructions for the o2 sensor replacement?
Or maybe a link to a website that has it?

thanks

Sprint

iTrader: (10)

get a 22mm open ended wrench... jack the passenger side up of the car.. climb under the car.. un screw it with the wrench.. follow it up to the engine bay.. un plug the harness and replace

KWheelzSB

iTrader: (1)

I'm having these EXACT symptoms w/ my '95.

92k mi.
60k major service was dealer performed @ 65k mi.
Fuel filter was changed 100 miles ago, again - (I swapped a new one in on a hunch it was clogged - apparently, that wasn't the source of my problem).

Here's the catch:

1) I'm NOT getting a Check Engine Light (CEL).

2) The ECU is yielding only a 0505 ("no DTC's to detect") code when I pull the codes.

3) The symptoms are intermittent (sometimes the engine pulls strong, other times it exhibits the same "power loss & bumpy accelleration" KINGMAX described.

QUESTIONS:

1) For those experienced with the K/S, is it possible to have a bad K/S and not get ANY DTC's from the ECU at all? (There seems to be a strong difference of opinion on this, here - I'm just trying to separate fact from fiction).

2) For those of you who had bad Knock Sensors, were the symptoms always occuring, or intermittent, like mine?

3) If I remove the K/S from the car, what parameters should I use to test it? (I have a digtal multimeter). Ie: am I testing for resistence, voltage, or what? -And what is the acceptable range for a properly working sensor?

Sorry for all the questions - just getting a bit frustrated w/ the Max & badly need to sort this one out.

TIA,
-KWheelzSB-

Sprint

iTrader: (10)

Trouble Diagnosis for DTC P0325

Knock Sensor(KS)

Component Description

The knock sensor is attached to the cylinder block. It senses engine knocking using a piezoelectrical element. A knocking vibration from the cylinder block is sense asa a vibrational pressure. This pressure is converted into voltage signal and sent to the ECM.

ECM TerminalS and Reference Value

Specification data are refernce values, and are measured between each terminal and the 25 ECU Ground.


Terminal Wire No = White
Wire Color = White
Item = Knock Sensor
[i]Condition[i] = Engine is running - Idle speed
Data (DC Voltage) = 2.0 - 3.0V


On Board Diagnosis Logic

*Freeze Fame data is not stored in the ECU for the Knock Sensor.
The MIL will NOT LIGHT for the Knock Sensor Malfunction. The Knock Sensor has one trip detection logic.

Diagonostic Trouble Code No. = P0325, 0304
Malfunction is detected when = An excessively low or high voltage from the knock sensor is entered to the ECM
Check Items (Possible Cause) 1 = Harness or connectors (The Knock Sensor is open or shorted)
Check Items (Possible Cause) 2 = Knock Sensor

ECM Diagram




Engine View



Diagnostic Trouble Procedure

INSPECTION START[list=1][*] Turn Igntion Switch OFF[*] Lossen and Retighten Engine ground screws[/list=1]



A



Check Input Signal Circuit-1[list=1][*]Turn igntion switch OFF[*]Disconnect ECM harness connector and knock sensor sub-harness connector[*]Check harness continuity between terminals 1 and ECM terminal 64.
Continuity should exist.

IF NG, repair open circuit, short to ground or short to power harness or connectors

If OK check Harness for short to ground and short to Power.[/list=1]
IF OK

Sprint

iTrader: (10)

B



Check Input signal Circuit-2
Check resistance between terminal 1 and engine ground.

Reistance:

Approximately 500 - 630 kohm

If OK, check harness for short

It is necessary to use an Ohmmeter we can measure more than 10 Mohm

IF NG

Check teh following:

- Harness for open or short between knock sensor sub-harness connector and knock sensor.

If NG, repair open circuit, short to ground or short to power in harness or connectors

- Knock Sensor

If NG, Replace knock sensor


IF OK

Check SHIELD CIRCUIT[list=1][*]Turn ignition switch OFF[*]Disconnect harness connectors "F23", "F121"[*]Check harness continuity between terminals2 and engine ground

Continuity should exist

If Ok, check harness for short to ground and short to power. Then reconnect harness connectors.[/list=1]
IF NG

Check the following:

- Harness connectors "F23", "F121"
- Harness for open or short between harness connector "F23" and engine ground

IF NG, repair open circuit or short to ground or short to power in harness or connectors.



Knock Sensor

Component Inspection




Knock Sensor[list=1][*]Disconnet knock sensor harness connector.[*]Check resistance between terminal 2 and ground[/list=1]
Approximately 500 - 630 kohm [at 25 degrees Celcius / 77 degrees Far]

- It is necessary to use an ohmmeter which can measure more than 10 Mohm

Caution:

Do not use any knock sensors that have been dropped or physically damaged. Use a new one.

KWheelzSB

iTrader: (1)

Wow Sprint. You like, uh. . .totally kick ****!

That info. should be a sticky somewhere, for sure - especially considering how many 4th Gen-ers seem to have problems with this little electronic gremlin.

Thanks a TON!



-K-

PS: Thanks also to fst96se for the great how2 pics. (although I think I'm gonna go the socket wrench w/ universal/flex joint w/ extension route, as opposed to the crescent wrench, "give blood 'till it hurts" route! )

Zero Gravity

should the Knock sensor be replaced first or the fron o2 sensor? Cuz I just got a 0304 and now I"m debating to where I should start.

time2reup

If you only have 0304 then you probably need to replace the knock, if you have two codes fix the other problem first and see if your knock code goes away....

TonyGotSkilz

iTrader: (6)

Sorry Dude your wrong

My knock sensor went bad and the ECU threw only the 3/4 code for about 3 months before i fixed it...I payed 175 for the OEM knock sensor, installed it myself (it was a *****) and know my maxine runs beautifully...The Knock sensor is a VERY important sensor actually. It listens for engine pinging and if it heres it or breaks it retards the HELL outta your timing turning you maxima into a sentra gxe =). I got beat by my friend in his ricey civic when my knock sensor was bad. raced him again after i fixed it and beat him by 4 car lengths.

magic_max

Why did you change your ignition coils? Just for the price? How will you test the o2 sensors once it's out of your car?


Thanks,

krismax

iTrader: (15)

I have a DATA LOGGER its a obd2 scan tool and a multi checker. One thing i find is that there are times when the computer knows there is a problem but does not turn on the CEL . This has been verified at dealerships,i have found this with other cars to. I have these stumbling midrange problems to,i have been clearing the knock code for a short time now.But maybe now i will try to find a cheap KS. The funny thing is when i turn the fan to level 4 at 650 idle,the timing goes from 11-13 to 13-17 degrees,air flow .43lb/min,load 20% air intake temp at 48f, everything is just about connected to the ECU little things lead to big things.