I got a 03 g35 6mt my car is lagging power a bunch. Took it to oreillys hook up the scanner and is putting out a bad knock sensor and i have no check engine light, doesn't make any sense to me. Does anyone know the problem please let me know or replace these bad boys thanks.

 

same issue, any luck finding out how to change it?

 

I think its under the lower intake on top of the block but I'm not sure. Probably just a wrench to remove it

 

yes you have to take the intake manifold off to change it . its also a good i idea to change the wire harness for it while your in there . the knock sensor code does not come up as an ses light but if the code is there its there for a reason . you will definately be down on power because of it .

 

Very rare the problem is the knock sensor..replace your injector harness and it'll fix the problem 9 times out of 10. Z1motorsports sells it, had this issue a while back

 

thanks, I got your message late. I did find the sensor. Takes 3 Hours. All you need is a towel, 10mm and 12mm ratchet to remove all the bolts. Once you take out the intake and the pendum, cover the holes with the towel so they don't get dirty. Your back will ache...lol The sensor is in the dead middle. Maybe consider changing the gaskets while your at it, doesn't need to be but would be good.


It does run better, but I need a computer to see if the code comes back. I will do this again, and change the harness also. I didn't do the harness the first time. I will also change the gaskets and spark plugs next time once the harness comes in. The sensor did not look damage but the harness did look OLD!!! like 100 years old. I regret not changing it hen, but had to get to work. Just make sure all the hose are put back in place... I forgot to reconnect one in the trouble and it started smokin LOL

 

you know i think z1 sells the knock sensor harness by itself now so you don't have to buy the whole injection harness set

 

For those who had a knock sensor code, Was the car losing power in all the RPM range or just in the lower band ?

Does it also happen all the time, Or only under specific circumstances ?

Thanks,

 

$38 from z1 nice that you can get it now with just that wire . when my car had the knock sensor code. i knew something wasnt right with the car for a while and that it had to have more power than it did , i got mine used with 97k and i had already had all that apart before to put in my plenum spacer . i was actually happy when the damn code came up . mine had been intermitten sometimes i had power other times not . after i changed it definately felt like it had more low end power .

 

My car has a severe power loss after the car is up to temp ( after warm up ), And when i checked the timing it was 15 at idle, But it drops to 10 once i move the shifter to Drive ( It's an auto ), Is this normal ???

Can a knock sensor be the culprit ?

 

its very possible that could be your problem , knock sensor or wire (change both ) . i had more low end but to be honest it did feel better all over . when my car was cool like yours it ran like a ***** but when it got warm and im guessing out of the open loop warm up mode it just didnt wanna go .

 

Can i run the car with the sensor disconnected, just to rule it out ?, Is the connector accessible without removing the plenum ?

 

i ran mine without it connected but it really didnt feel any different probably cause it wasnt getting any signal from my knock already . you can unhook it from underneath the car just have to find the connector .

 

Whats the link for this Z1 part?

 

http://www.z1motorsports.com/350_g35...oducts_id=5833
http://www.z1motorsports.com/350_g35...oducts_id=5719
ebay has the knock sensor for way cheaper.but dont if there as good as nissan ones. but thats better price on z1 then the dealer charges for it for the oem nissan sensor