liqidvenom

iTrader: (6)

my ks has been bad for sometime and i didnt really notice how bad it is. i used to race my friend with a modded spec v and i would put a couple of cars on him when ever we ran. tonite he put a car on my and just puled hard on me from their. since then i added pulleys and his car is still the same from when we raced before. so i know the ks is slowing me down but i didnt think it was by that much. i pulled my codes and i got y ks code from the ecu and i have a couple of questions.
1. i already replaced my ks last yr at this time when it went bad and im wondering if there is something that might be causing mine to go bad so quickly?
2. my friend wit the spec v took his ks off and he runs thick wire from the block to where the ks is normally plug up. he runs this and always runs super at the pump. he's had this setup for a while and he says that it works just fine for him. i was wondering if any maxima owners have tried anything like this or if its even possible for us to try. also do we have the same ks as the spec v?
3. are there any alteratives to replac our ks so that it wont fail again. cause i have replaced one already and they arent cheap and i cant see me doing this more then once again.

thanks for any imput,
will

knight71

Check the how to stickies in how to check the resistance on KS.

larryseibel

iTrader: (8)

the knock sensor helps the ecu controll engine timing, air fuel ratio and egr activities. a knock is actually spark detonation. it means that your engine is firing before the spark plug fires. this is due to compression and high combustion temp. your ecu can do things like open the egr valve and change the air fuel ratio to get your car to stop knocking. running higher octane gas like 93 octane usually helps alot because the higher the octane the higher temp the "explosion" or combustion is. but you kind of need it so that you dont throw the c.e.l. and so your ecu knows how the car is running.

nismos14

iTrader: (56)

you may have over tightened it or broke the ks when installing it the last time. did you buy the knock sensor used?

Luvs2speed

yeah man first thing you can do is run atleast 93...manual says 91...forget it, use 93 or 94......only way you can make sure you installed it correctly is to test it with a voltmeter and get a torque wrench-I think maybe 15lbs to 20lbs is how hard it should be tightned

liqidvenom

iTrader: (6)

ok maybe i wasnt clear when i first posted this. i always run 93. i read the stickies back when mine when bad the first time. and i know what the ks is for and what it does and how it does it. i also know how to check it.

what i was wondering if and maxima owners have tried to ground it to the block so that it is less sensitive but still recieves a signal. like if u remove the ks and attach 10guage wire to it with eyeletes on both ends. one end to the ks and one to the bolt the goes between the v in the block. i had meeta couple of sentra owners that have had issues wit their ks and have used this method for a while. when i get back from work ill post some links to what im talking about.

Harmony

Could this explain why I'm pulling a KS code and an EGR code at the same time?

liqidvenom, I'm not an engineer, but I defintely understand what you're talking about. Its interesting, but I cant really comment on it since I dont study engineering. Your question is: will thicker wire guage prevent the KS from being damaged? In order to answer this, you would need to prove that the KS was being damaged by low/inconsistent current by the present wire/harness you have right now. I havent seen any known causes to the failure of a KS. But I'm sure they're lurking around somewhere. Find the reason for the damage, and you will find the answer to your question. I'm guessing it cant hurt to try your friends experiment.

PAREDLINE

Knock sensors are damaged by the same things that damages other sensors. Heat, vibration, electrical fields, and material properties (the stuff it's made of).

Most sensors are nothing more than resistors. Its like the fuel level sending unit. After a while the thing just wears out.

I would not recommend removing your knock sensor and driving with it off. Its my impression that your friend did that.

DR-Max

iTrader: (3)

If you haven't changed your plugs and have over 30k on them (copper), 60k (platinums), then perhaps they are setting off the 0304 code. This happened to me not too long ago. I got the KS code and was ready to buy one when it hit me that I haven't replaced my plugs and I know its overdue. I put a new set of NGK V-Power coppers and the KS code disappeared. The car performs a lot better now, its like night and day.

NmexMAX

iTrader: (22)

Check the resistance to see if it is indeed the KS taht's bad, it could be the wiring harness. People have re-located it, it's in the stickys. I wouldn't do that, but it has been done.

ShRapNeR

iTrader: (1)

so bad spark plugs can trip the ks code?

NmexMAX

iTrader: (22)

They'd have to be pretty bad, so it seems like a rare case. If you know your plugs are bad, change them out to coppers and take the time to do it. SHould be approx $10 for all 6 in copper form. Most likely it's your KS though. Start at the bottom cheapest and work your way up to see what actually helps.

DR-Max

iTrader: (3)

The plugs on mine weren't falling apart when I took them out, but the electrodes where way rounded. Many codes can set off the KS code.

ShRapNeR

iTrader: (1)

im getting the ks code and the emissions control system code... although i have been noticing the car running like crap. hard to crank ect.. slow acceleration.

what exactly could be wrong with the "ECSC"

and what other things could set the ks code off

NmexMAX

iTrader: (22)

EGR and O2 sensors, but when the KS code is stored as a ghost code, then that usually means it itself is bad. The only way the KS code will cause the CEL to come on is when there's something else associated with that code, such as EGR or O2 sensors, but the KS could be bad for a long time, and unless you check the codes just for the heck of it, and discover the ghost 0304, then more thatn likely it's the ks that's bad on its own.

DR-Max

iTrader: (3)

Process of elimination.....

Go with the cheapest repair. With those types of symptoms your looking at may different causes. Hard starting can be anything from dirty throttle body to coolant temp sensor. Poor performance could be bad plugs, dirty throttle body, dirty idle air control valve, ignition coils, etc. It could even be tire pressure. Many of the ECU codes associated with the symptoms above can set off the KS. Pull all codes and fix other issues accordingly. If after all have been fixed or replaced you still get the KS code, then the KS is most likely bad, again.

liqidvenom

iTrader: (6)

here's kinda what i have been talking about. http://www.nissanperformancemag.com/.../knock_sensor/
if u read the article it says how after adding some mods to the car, that can increase the amount of vibrations the ks can and will pick up. my question was since this works for the qr25de motor i was wondering if it would help us out and reduce the number of times we need to replace a ks that has become over sensitive. also on their forum it had helped some of the more modded spec v's gain hp across the board. i'll find that link in a minute.

liqidvenom

iTrader: (6)

here r the follow ups on the first link.
http://www.b15sentra.net/forums/showthread.php?t=94422

http://forums.thevboard.com/viewtopi...26f6e6405a12e4


this is what im talking about with the ks grounding and all. i think it could be intresting if it worked for us also.

DR-Max

iTrader: (3)

So they relocated the knock sensor to the firewall? I'm not sure about the feasibility of this mod. Vibration spreads everywhere, kinda like soundwaves. Plus, the engine is still mounted on the vehicle's frame and inturn the body of the vehicle sits on the frame. Any vibration from the engine, is felt thru the frame and thru the body or in this case the firewall. However, the main concern here is not just vibration but knock detection. I find it hard to believe that engine knocks can be detected once the sensor has been relocated away and off of the engine block. There is a good reason why Nissan engineers put it there. The knock sensor is insurance against detonation when it senses knocks within the engine. Why lessen the effectiveness of this device by relocating it elsewhere. If the knock sensor is always out, there must be a darn good reason why but don't just blame it on the knock sensor or its choice location. My 3rd gen had over 300k miles and my previous 4th gen had almost 200k and neither one had seen a knock sensor failure. My current 4th gen have been showing the KS code but as a secondary code of the first codes which is usually the culprit. If you notice, the author of the article below added this to the article as insurance for him as well just incase people try this mod and end up blowing their engines because of the knock sensor's inability to do its job ones relocated. It said: "First, I suggest that you run with the highest possible octane gas at all times if you do this mod. Higher octane gas burns more efficiently making the engine less prone to detonation. However, at higher loads or on hotter days, you may want to run octane booster or race gas mixture." . Think of it this way, if you are running super high octane fuel, then the chances of detonation are almost nil. Whether or not the knock sensor works, it won't matter because you are using the type of fuel that eliminates the very thing that the knock sensor is there to detect.

I've read a lot of these articles around but I don't really see the validity of it. Engine vibration and noise is by far distinguishable from an engine knock or detonation in my opinion.

liqidvenom

iTrader: (6)

like i said before i always use high octane gas. and i thought the ks senses its knock by picking up vibrations from the motor. and i would asume that relocation it would help reduce that.

DR-Max

iTrader: (3)

I read what you said before. Why worry about knocking (from detonation) if you are using high octane gas? The only reason why detonation occurs is because of low octane gasoline.

liqidvenom

iTrader: (6)

im not worried about knocking its just that my ks is pulling the timing and making my car slower

DR-Max

iTrader: (3)

Well that is a little weird. You are using high octane yet the KS still retards the timing, there's something else wrong. I'd say comb thru the stickies. I'm not sure what to tell you now.

larryseibel

iTrader: (8)

just replace the knock sensor. inside the knock sensor is a special kind of crystal that generates electricity when a certain frequency (vibration or knock) is felt. this frequency is so specific that it can only be produced by detonation. this tiny bit of electricity is sensed by the ecu and changes are made to stop the detonation. if you got a knock sensor code...unless there is something wrong w/ the wiring...you have a bad sensor. grounding it out or trying to make it less sensitive will not work.

liqidvenom

iTrader: (6)

i gathered that i have a bad sensors. that much i can tell. i just dont see y mine seems to go bad so quickly.so i was looking for a way to prevent the next one i get from going bad. i think if ur car knocks or the sensor goes bad then it pulls timing and i know my issue is the later

Bender-san

Older Nissans (older than 02) will set knock sensor codes with perfectly good sensors. Every Maxima I look at that's older than 02 (between 6 and 15 a week) has got a knock sensor code. The nice thing is that the code will not set the MIL on. If you've got a problem with power up top, it may be due to your MAF starting to take a dive. I've seen MAF sensors do WIERD things to Maximas when they fail...and they may not even set a code when they fail.

liqidvenom

iTrader: (6)

hmmm finally i get a good answer. is it possible to check to see if my maf is dying on me?

liqidvenom

iTrader: (6)

also if the ks throws a code how do i go about getting it to stop throwing the code even after i clear the code.

DR-Max

iTrader: (3)

Check for voltage by backprobing with voltmeter. Probe the first terminal from the right and if it reads below 1 volt with the key in the ON position, engine not running, then be prepared to spend a few hundred dollars on the sensor.

If the KS ghost code keeps popping up eventhough you've replaced it, something else is wrong. That's the point Bender-san was trying to make. Even with cars with new knock sensors, the ECU would still throw the ghost code for no reason. And in this case, the MAF sensor could be the problem......good point Bender-san! I'll make sure to bookmark this thread for future reference, I'll probably check the MAF sensor on my car this weekend to find out where its at. Liqidvenom, you can't just make the KS code or any code for that matter go away until you have totally eliminated the culprits leading up to it. Unfortunately, our cars are at that point where everythings starts to go wrong. It's just a matter of keeping up with all the things that break and fixing it right away.

larryseibel

iTrader: (8)

MAF=mass air flow...its the sensor that is in your intake plumming before the throttle body. i think that is highly unlikely. the MAF can make a car do weird things but not usually w/ the knock sensor. i would be shocked if you have a bad MAF. i have seen a bad MAF throw oxygen sensor codes and fuel trim codes but never a ks code.