My car drives fine, and I currently have no CEL's. However, when I check for codes with my Scanner, just for the heck of it, I get 0325. This is the code for a bad knock sensor. I checked last night, 3 months ago, and 6 months ago. It's always there, and never a CEL. Also, what is weird is that my scanner won't erase the knock sensor code from the ECU's memory. When I did have other codes (bad o2 sensor) and took care of my issues, my Scanner would allow me to erase all codes, but not the knock sensor code. What gives?

BTW, the reason I'm checking for codes is because my car doesn't feel as fast with my butt dyno lately and I'm not hitting 10 psi like I used to. I've done quit a few mods lately and I don't know if I've screwed something up, or if my knock sensor is hurting me.

And no, the lightbulb is not burnt out. It comes on when I put the key in the ignition. Also, when I get other codes, it lights up. I currently have 120k miles and am boosted.

Any input would be greatly appreciated. Thanks!

 

the KS code is a ghost code meaning it does not trigger a cel light. only a scanner will tell you if you have a KS code or not. nothing bad...dont worry.

 

from personal experience it will never trigger a light. when you clear the code does it come back instantly? Generally speaking it should go thru a couple of drive cycles before it triggers it back up again.

 

ghost code... hmmmm... well it shows the code in my car... 0304... thats it... right?

this is what i think is going on... when i used a scanner about 2 months ago it used to show me the front right o2 sensor code. but no CEL light for it turned on... it finally did turn on... but thats when the o2 sensor was taking its last breaths... or mayb dead...

so mayb u're knocksensor is going to go out on u soon... so the scanner is letting u know ahead of time... the CEL will turn on when its gone...

this is just my opinion...

 

And it's wrong... The reason has already been explained.

 

like i said....your ecu is throwing a code....but it is not going to trigger the cel. so in actuality....you do have a thrown code for the ks by ur ecu you just dont see it. thats where the scanner comes in handy.

 

Like I said in my first post, I can't erase it. Weird.





Also, I thought 0505 was the infamous ghost code, not 0325. So you guys are saying Nissan designed a car and determined that the knock sensor isn't important enough or whatever to trigger a CEL? Only indicated by checking with a scan tool?

If it's a "ghost code" as you call it, how would one ever know when is the proper time to replace the knock sensor?

Any more input? I still don't know if I should replace it or not. Thanks.

 

from reading other threads like this, i'd say that you need to change that KS and you will get your power back

 

FFS

0304 = Dead knock sensor [Will NOT trigger CEL]
0505 = Nothing Wrong - Nothing Detected

Ghost code = Error code that doesn't turn on the CEL

You should always be able to reset your ECU.. and get the 0505 but on starting the car you may get 0304 detected straight away if major knock

Some codes are only trigger CEL after they have occured more than once since last startup

 

Thanks for the input killer... I don't have a Hayne's in front of me, but I assume 0304 is the CEL flashing code, and 0325 is the equivalent scan tool code?

It's always been my understanding that a ghost code is really a "shadow" code, meaning that when something fails, another piggyback, or "shadow" code comes with it. Then, after fixing the first problem, the ghost code will go away by default. You describe a ghost code differently.

Again, my scan tool will not erase my 0325 knock sensor code.

 

k i'm getting the rear 02 sensor and catalytic converter replaced today... so after that the only code remaining will be knock sensor 0304... let's c if it'll trigger the CEL...

 

ok i have a 95 max and the cel is on. i got it scanned and they said it was the knock sensor. How does it not turn the cel on...it did for me

 

you are changing the rear O2 sensor but ignoring the knock sensor? you do realize a new knock sensor will give you more power and better mileage than a new rear O2 sensor right?