Got 112K on my Maxima and just had the service engine light come on. Took it to Autozone and the error code came up as a knock sensor & vacuum pressure i.e. multiple codes (4 in all) may be they all triggered simultaneously. Reset the computer and went on my way. No drivability issues so far. Would appreciate any advice on this subject. BTW how much does it cost to replace a knock sensor at the dealer?

 

ask the dealer. PArt is expensive 1bour 175$. Some dealer might charge lots of labor, when in fact you can do it in 30 minutes. before replacing the knock sensor, fix the other codes. The KS is often triggered by other systems malfunctions by domino effect.

 

do it yourself for 107$...90 for the sensor 17 for tools













www.skippynet.com

 

True, knock sensor could be caused by domino effect due to other problems but, if KS is your ONLY problem, it doesn't always trigger the CEL. However if you still pull codes, you should get a KS code even though the CEL isn't on. Correct me if I'm wrong anyone.

 

you are correct sir...

 

should be noted that knock sensor replacement is possible in 30 min IF IF IF you have small enough hands to get down in there.

or an UBERWRENCH (ie bastardization of every tool/extention i could get my hands on)

write up

 

Thanks everybody for the feedback. The CEL has not come back on and I still haven't had any driveability issues. I've put on 50 miles after the code reset. Should I do another code check at this point as one of the posters mentioned that a knock sensor fault may not always result in the CEL. Or should I just drive on

BTW if I am using the recommended 91 premium why do I need a KS? I thought the only function of the KS is to control ignition timing to prevent premature detonation if a lower grade fuel is used. Will a faulty KS result in damage over time?

 

Just drive on until the CEL comes back. If the CEL does not come back for a few days, check it for the KS code.

If your engine is under heavy load or something, it can STILL ping/knock even with premium fuel. A working KS will help save your engine or something... Read the FAQs at the top of the forum

 

How much can I expect to pay for a KS?

Any links to a cheap KS?

Thanks

 

cheapest ks are $90 on ebay

 

Courtesy sells the kit with KS and harness for $159. If you are not sure the problem is only the KS, this is the way to go since the harness alone here in Canada is $90.

 

Go to the sticky on 4th Gen How-Tos. I and others have written extensively on diagnosing, purchasing and replacing KS.

 

I don't know if this helps but a few eeks ago I also got a check engine light. I had my mechanic run a diagnostic and it came back as a camshaft sensor. It cost $100 but the car has been fine since.

 

I rechecked the ECU codes even though the CEL was not on and I got P0325 and P0466. I believe the first one is for the KS.

 

is the CEL reset the same thing as the ECU reset???

 

yes



*sigh*
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