SE Maxima

The debate over the knock sensor drives me crazy. I have been getting the 0304 code for months and finally decided to replace it. I called a local dealer for a price quote and he said they almost NEVER replace knock sensors. He said I'd be much better off replacing the oxygen sensors (I'm getting those codes also) since they are likely tripping the knock sensor to code also.

I still think I'm going to replace it (from Courtesy, of course) after all that I've read on here and Motorvate, but it's odd to get such directly conflicting info.

CRiME

iTrader: (21)

Definitely replace it. Not only will you have a noticeable performance boost, but it will practically pay for itself over time, in the $$$ you will save on gas. Do it ASAP!

BigLou93SE

iTrader: (10)

Fix those other codes first, and reset your ecu. It very well be getting thrown becuase of the other codes. If your knock sensor code comes back after fixing everything else, then yes, change your knock sensor yourself.

incognito903

iTrader: (2)

yeh man im in the same boat as you. apparently ive been losing 40 whp for the past 8 months with the knock sensor DTC being active...? i have to buy this part. the knock sensor code is a definate faulty part right? i remember the thing said a faulty one will always fail the test but a good one might not pass?

smotz

iTrader: (3)

Replacing my knock sensor was the biggest performance mod I ever did no bs.

Scooobay

iTrader: (5)

im getting knock sensor code but p0335 or somein like that...i replaced the knock sensor ( with a used one ) ...still pulling the code..knock sensor i replaced it with was probably bad too ....should i look to rpelace 02 sensors?

DragonMaxima

iTrader: (7)

A knock sensor code is always tripped by something else. Make sure you clear up those other codes first before changing the knock sensor.

SE Maxima

Thanks for the input guys. I plan on replacing the KS as soon as possible. My car definetly doesn't feel as fast off the line as it used to...low-RPM punch is not great. With 150K miles on the car I'm sure it's overdue. The O2 sensors need to be done also, but that will be another day...

Anybody know if you need to replace the wiring harness with the KS?? Courtesy sells the two items together.

thanks....

Blaxima95

You shouldn't need to replace the harness. I've done 4 KS's and I'm about to do my 5th and the harness were fine on all of them. Just make sure you take your time removing the connector from the sensor. Remove the sensor first, then disconnect it.

BigLou93SE

iTrader: (10)

Why do you feel like ignoring good advice?

Fix the other problems, and then if the KS code persists, fix that. It might not even be bad (as rare as that would be at 150k, but still). Fix those o2 sensors, the KS code often is triggered with that.

Or do them all together at once. But if it's one or the other, concentrate on the o2 sensors, and see if your ks code stays away. I'm sure part of your performance problem is from the o2 sensors too, as well as bad gas economy.

Tim96I30t

iTrader: (2)

You can test it with an ohm meter to see if it is good or trick it with a 470K ohm resitor. The 470K ohm resistor will stop that code and see if you have others. Don't do this for an extended period or when you will be driving over aggressive, YOU HAVE NO KNOCK SENSOR.

Guinader

iTrader: (1)

the reason why teh dealer said that, is becasue they folow the manual procedure which requires the removal of the intake manifold... they it cost you alot of money.... DIY saves you alot of money... that is all...
canclusion: DO IT!!! YOU CAN DO IT!!

overcastfab

sorry for the noob question, but how do you know when to change your knock sensor? i searched the FAQs and i'm assuming the CEL will come on? and has anyone gone 130k+ miles without changing the KS, or should the KS be changed every xxx miles?

NmexMAX

iTrader: (22)

Quoted for truth

You obviously have not searched enough.

Not if it's a ghost code

SE Maxima

I'm not ignoring good advice. I don't have a good place to get my car on jack stands and replace the O2 sensors (I live in an apartment). Plus, the KS code has popped up solo when I've run my codes in the past. Pluuuuuussss, I only have so much time off (vacation in 2 weeks) and I need to get something accomplished. So I'm going with the KS first. The O2 sensors will come later...

White2theMax

No, a knock sensor will not make the CEL come on!!!! It never does. You need to do a Self-Diagnostic on the car to know for sure if your knock sensor is bad. A bad one will give you horrible low-end power and reduced gas mileage. Check the freaking stickies. Jeeze.

zander

iTrader: (2)

Lol owned by a newbie

Guinader

iTrader: (1)

fresh from the batch too.... less than a month

I30tMikeD

iTrader: (8)

You might just be wasting your money though.

Replace o2 sensor first, then if there is a knock sensor code still there after 50 or so miles of driving and no other codes present, replace knock sensor.

maximaman10

I would replace it. You will get better performance. It is not something you have to replace because it just retards the timing to stop the knock. I replaced mine and am glad I did for performance reasons.

SE Maxima

Well I finally had time to replace my KS and it was definetly worth the price. It's hard to say whether the car actually runs better or if it's just placebo effect, but it does feel smoother and more powerful than before. Especially low RPM range. I'm going out of town this weekend on a road trip so I'll get a better idea about gas mileage then.

The term bloody stub is about right when describing what your hand will look like after digging that SOB out of its hole. And I have small hands. Couldn't imagine what a big-fisted brute would go through.

Incidentally, when I took the old KS out, its black plastic casing was cracked the whole way through. Looked like someone had tightened the bolt down on it way too tight. If I could figure out how to post pictures here I'd do it. But seeing how I'm a rookie with that, maybe later...

peace

maxrepairs

My experience was the same as yours. When I pulled the knock sensor out the car definitly ran better and the code went away. It was also cracked.

BigLou93SE

iTrader: (10)

Although it seems as if you needed the knock sensor anyways, it still would have been your best bet to replace those o2 sensors. Good job on the install though, I remember how much determination and mind over matter thinking it took to get my hand into that trap. Get some good o2's in that bad boy, and really see how smooth and efficient your car can be.

MaxedOut99SE

iTrader: (8)

Yeah thats true, I remember when my engine light came out and I had to replace all 4 O2 sensors and the knock sensor. I'm glad I did and haven't looked back since.

99se5speed

iTrader: (8)

95bluse

iTrader: (1)

As someone else said, if you're not sure, just try the resistor bypass method and drive it for a couple of days. Check your codes during this time and look for a performance boost. If your codes disappear & car runs 100% better, your KS is bad.

Take it from me...my resistor is still in there....5yrs later

clive

All FOUR?

NmexMAX

iTrader: (22)

Cali-spec.

SE Maxima

Well, your original advice about fixing the O2 sensors first was good. But I have been getting the KS code for so long (and many times all by itself) that I figured it couldn't hurt to change it out. And my old one is pretty much cracked all the way thru one side. I ran my codes after doing some driving with the new KS in place and I am still getting a front O2 code (0503 I think??). Big surprise, huh? Later this summer I want to get a new Y-pipe, so I'll probably try to do that and the O2 sensors at the same time. By then I'll actually be in a house with a garage instead of an apartment and will have some space to do the work.

Thanks for the help fellow ORGers!!

crazyrodent

my hand had a few small scratches. it wasnt mangled like everyone makes it out to be. just move your hand slow when you put it in the hole and you should be alright. wearing mechanics gloves dont help because they get caught on all the pointy objects
someone with giant hands should definately not attempt this

MaxedOut99SE

iTrader: (8)

Yeah man, I have a 1999 Maxima SE.

It takes 4, 2 before the cat and 2 after the cat. I was suprised myself, earlier Maximas only had 2.


I replaced those 4 sensors along with the knock sensor too..

I don't know bout the car being a Cali spec because I'm the only owner of the car and I brought it here in New York. Unless cali and New York requires vehicles to have the same clear air specs for all cars, not to sure though

sonicrunch

Why does everybody get bloody hands. Are you all stupid?
I used a magnetic pick up tool, and never had to stick my hands in there..