I think my knock sensor might be failing but not throwing a code. If I put a 470k resistor do I need to reset my ecu? I did put it in for 2 days then took it out because I didn't notice a difference. But I drove it like 75kms max in that period which I don't think is enough to re program itself. Anyways thanks for the help!

 

reset wouldn't hurt, but I don't think it's necessary

 

http://forums.maxima.org/5th-generat...t-failure.html


See post #11.

You posted in that thread too...

470 Ohm is the wrong value you're telling the ECU the KS is cold, even though the ECU sees the engine is warm. This 'test', if you can call it that, with a 470 Ohm resistor won't tell you squat

 

Ohhh.... Everywhere I read said they used 470k risitors and the people that used them said they worked. Wouldn't it be more logical to use a low khm resistor being that it has more power when cold because it fully retards (or advances can't remember) timing to produce the most power? If you use a higher khm risistor it does the opposite poriducing less power

 

They work just fine. I've used one in my last two cars. Check under my hood right now.

 

^It'll work with it unplugged too


The point of your test with the Resistor is to mimic the Knock Sensors normal operation. It's normal operating range is 500-620k Ohms.

Most guys used the 470k on the 4th gen, that's where that came from, and IIRC the Resistance values of the 4th gen are different too, and the 470k was in the operating range of the old KS. I could be wrong here I don't have the 4th gen FSM anymore to verify, but someone should.

As far as a lower Resistance being better/worse, it doesn't really matter, the ECM just wants it within that range. It's not a temp sensor, engine management is not affected differently when the KS reads 500k as opposed to 600k. The issues come into play when the reading spikes/jumps around.
So in theory, yes, the 470k works, it's better than a broken KS or no KS.

BUT it's not the correct resistor to use if you're trying to mimic the KS, so why would you use it

 

FWIW - when I had to replace the KS on my 4th gen, I measured the new one (Nissan oem) before I installed it and it was 560K ohm.

 

Another thing to check, that's often fogotten about, is the small grounds (8mm head IIRC) under the cover in the center. That KS Resistance value is Resistance to ground, not internal resistance in the KS, so if you have a lightly corroded, or loose, or otherwise comprimised ground closeby, you will get an improper reading. Remove, clean and reinstall these grounds:

 

Ok good to know. My car is under powered and has a bit of low end hesitation once it hits 3000 rpm it takes off and drives good, I know this is nortmal to an extent but this is a huge difference from low end power to high end power, I heard that ks wil affect cruising. More than wot because whpponce you hit wot timing is set a a specific degree and the ks is elimintaed I thought I would give it a try. The only other thing I haven't tryed was adding a ground which I heard helped people in some situations. Would you know what guage ground wire I could add and where should I add it to ? Block to firewall, tranny to frame, block to tranny, block to rad support???? The issues I'm having are. Hesitation only under 2000 rpm which is far more noticeable when cold but still there when warm, what feels like loss of power under 3000rpm sometimes shifting feels a bit off like to low rpms for that gear ( like I'm towing a trailer but I think I'm feeling this because of the loss of low end power. So manly loss of low end power and low end hesitation I also had hard starts but if I keep it above a 3/4 tank its starts fine. Things I have done, cleaned and tested are the following, cleaned maf,tb iacv, replaced upper plenum gasket, maf, cts, fuel pump and filter,air filter, plugs (iridium) pcv,, I have checked fuel pressure, tps, batt, alt, I'm sure there is more that I can't think of, if anyone has had simular issues with low end hesitation please let me know you. Solutions! Thanks guys!

 

Tunermax3000 u are 100 percent correct i looked back at this posting and decided to throw a 570k in there..... holy smokes!!!!! definatly alot morepower. it feels the sane at WOT ...WOT always felt good it was just cruising around and tryin to gun it.. it felt weak. not any more. im startin to really love this car. i put that resistor in, drained my tranny fluid cuz it was a bit overfilled and a new tps plus the thousands of other little things ive done and it feels great!!!!! So for future 5thgeners .. 570 not 470 k ohm

 

^Glad to hear it man! Always nice to get some ponies back, and when it comes with better fuel mileage it's a big plus!

 

So now is this a mod? To trick it into think your at wot all the time or just to fix a bad knock sensor?

 

for sure!!! its amazing how much more of a pull i can feel... its just overall a better feel when driving ... thanks a bunch!

fishtale- i beleive its just a "temp" fix to a bad ks.... i will be replacing mine when i have the time at work. it helps to determine if your ks is bad w/o removing plenum or scuffin your hands up real bad hahaha.. but i reccomend anyone who has a power issue... spend the 50c and get a 570k risistor and throw one into ur ks harness it takes 50c and two seconds to discover alot more power! thanks tunermax 3000.. i feel bad with everyone with 470's lol cuz there is a huge difference between the.two

 

I wouldn't say "fix" a bad knock sensor, but rather eliminate or bypass the knock sensor.

 

This. All you're doing is bypassing the sensor. You should be replacing it, this is only designed to be a TEST procedure to find out if you have a bad Knock Sensor.

However, many people don't replace the darn KS once they install the resistor and it "fixes" what they feel.

 

would doing this bypass actually cause damage to the engine.if i remember the knock sensor is there to help advance or retard timing and bypassing it and using cheap gas could damage the engine.

 

Yes there is that risk. The main purpose of the Knock sensor is to spot any pinging or knocking in the engine, if the Knock sensor is bypassed then this sensor is disabled, and the engine could ping, knock all it wants without the ECU having a clue.

This is why it's a test procedure, but people run the risk instead of getting in there and changing it/spending the money. I wouldn't do it, but guys do....

That's why the engine goes into a form of "limp mode" when the Knock sensor is bad, to protect the engine because it can't monitor for pinging anymore. Essentially, the knock sensor allows the ECM to advance timing to near-threshold limits, which squeezes out a whack of extra power and also, fuel economy. this is why the correct fuel is so important on these engines, and why the Knock sensor should be working properly at all times.

 

Lol dennismk?.... Well im glad you chimed in with your little dumbass remark.. thanks!! it does fix the issue of a bad ks.. but all your doing is fooling your ecu... is that better for you ?? i hope your happy with this updated info i put on here im happy there are people like you to come on here to put a smartass remarks like you did.... n e ways lol yes in no means should a resistor be left in... its just a way to determine if there is an issue with the k.s u have installed on ur vehicle.. Thanks again for the useful and much appreciated info from tunermax3000 and others who have contributed "useful" info to this site..

Dennismlk or whatever SUCK MY DUCK ... thats right.... duck ......

 

huh? ^^ Where the heck did that come from I don't see anything from Dennis that is questionable?

even if there was, that's way over the top dude take it ease.

 

DennisMik does nothing but good for this site. So I'll pretend I ddin't read that.

Aside from that, I agree with Dennis.

 

No.. how was that over the top? by saying smart ***? by re phrasing it for his benifit? Do u see a point of his post " i wouldnt say fix it" i never said it fixed my k.s. just fixed my symptoms of a bad k.s. and i would be later replacing my k.s. he might do good... im not tryin to bag on him but really.. was that a ness. remark? after all thE talk of how this is a temp fix TO FOOL THE ECU BEFOR HIS COMMENT WAS MADE?? nobody said "hey just put a resistor in and leave it cuz u just fixed your problem.. its put a resistor in... discover your problem.. and replace with appropriate parts... im not trying to create issues here.. but.... i get really annoyed with people who bag.on other peoples threads(not that he is really) its just frustrating when a pointless comment was made. did he give any useful info in that reply that wasnt already stated?? was there anything else he said in that thread? nope.. i bet he is helpful , but that wasnt and came out to me as a pointless remark. thats one thing about this site that i find diff. from any other auto forums is there is alot of hate and attitude.from people when a question is asked. just look through some of the threads on here ... its rediculous. someone asks a simple question and there bagged for it.. one person sees it and everyone gets on the bag train befor a mod. steps in to reconsile or remove the thread.. its a poorly maintained forum there was one guy.who was going to put a intake in his max from a civic.. it was three pages of people putting the poor guy down.. makin fun of him and his idea... who cares what he does he was looking for "positive" info if you dont have any move one to the.next thread...it was three pages of pure hate befor a mod decided it went to far.... all im getting at is pointless remarks make me upset.. its in my eyes unnessisary and a waste... yes i realize what i said is not appropriate and i over reacted. it just ive seen so much of it.on THIS forum i snap at the smallest thing...

nmexmax... your not god! u may be a mod.... but your not god! you remember that, u will never be saved from the powers of christ .... p.s. if you do ban me now i will sue you on the fact u banned me because of my religious views thanks in advance.may the lord be with you

cant we all just be friends here?

i didnt read fishtales comment!!!!!!! hahahahahahahaha lolololol im sorry dennismik oh man... AM I AN *** OR WHAT.... my appologies to you seriously lololol anyways... im sorry. dennis i thought you were just "correcting something i said you know? well it nice knowing you all.. ill try and send dennis a.pm appology befor i get banned hahahahaha its ok... i deserve it hahaha

 

 

 

I used a good KS, too, there was no difference, so I just left the 470 in there.

 

Life is good and we can put this to rest. I vote we all have a Merry Christmas.

 

^ While I am with you, I do wish I would never have helped this guy, what the ever-living heck is going on in this world man.

Merry Christmas!!!!

 

Goodness guys when you feel yourself getting angry just go race a civic. It will all be ok

 

I once contemplated a GSR ... w/VTEC y0 !

 

Ive been keeping this one for a rainy day. Should have shopped the language apologies.

 

because racecar.

 

It looks like it didn't have license plates yet. Like that guy I saw on today's news, gets a new Lamborghini (spelling?) and crashes it the same day.

 

I found this a few weeks ago http://rumors.automobilemag.com/mise...ris-92383.html I will warn you....Its sad

 

maxturner3000 sorry you decided.to help me... i need your help again my coc is.stuck in your moms vagina

 

Hmmm Manny......... crack the whip man you can't allow that (and not cause he directed it at me, just period.)

 

Wtf?

 

wow dude. This is a forum where we talk about cars and get off topic in a hurry. Not insult people that you dont even know

 

bumbaclad

 

you cant even spell your insults right. its a bumbaclot and yours is obviously filled to capacity because you apparently have a very heavy flow this time of month

 

Heavy flow.