I've got codes for both knock sensors. Do both go bad at once? Could it be the harness only? I've done a search but can't reach a conclusion about plenum removal on a 97+ to get the knock sensors. What has to be removed? How hard is it? I saw the pictures and it looks like they could come out easily after removing the fan/shroud and a couple of belts. Any advice is appreciated.Also, has anyone used aftermarket parts? Dealer wants $168 for ks and 65 for the harness, Whew!
Modified by bullittandy at 6:44 AM 3/29/2006

if you email user "ceningolmo" he has a set of 2 brand new KS for $200 shipped... new in box nissan genuine...

you gernally want to replace the harnessand the KS when doing the KS job..... Its not terribly hard, the plenum doesnt have to come off

I did my knock sensors and harness a year ago. I don't know how they could be done without removing the plenum.

I did remove the plenum and fuel rails.

I didn't have codes, but the car was running very sluggishly, especially in warmer temps. Once they were done, the car has run great.

One thing I found was that the plastic "fingers" on the tips of the fuel injectors were very brittle and I broke a number of them. I was nervous I might have issues, but no problems have arisen in 15k miles.

The absolute key is to use tape and a marker to define which hoses go where.

When everything's apart, you should definitely clean the throttle body.

If you have any specific questions, and I don't get back on NICO quickly enough, email me directly at [email protected]

Don

Look at my previous posts and you'll see how its done to beat Flat rate . Cheers!

I replaced both KS and the harness, removing only the alternator, fan and coolant hoses. It wasn't too bad and beats the $800 labor quote I got.The car runs great now!

good to hear. how bout pics and writeup?

This certainly applies to a 97 and likely through 01. Sory no pics (see farfetched writeup)Items to be removed:-Engine cover-Engine fan-Alternator (lower mounting nut had to be taped to case to hold it on during assembly)-Upper radiator hose-Aluminum radiator neck/hose (attached to above)-4 inch rubber hose under plenum (attached to Y-fitting) This hose likely has to be cut off, I purchased it from the dealer, $13 but it could be matched at autoparts store-Knock sensors-obviously, they look difficult to get to but came out with a 1/4 socket wrench-wiring harness The new knock sensors are difficult to get in (starting the bolts) but truthfully it could be done in 2 hours the second time around

Moral of the story:97+ Q owners with a minimum of mechanical ability (brake job ability) can make this repair, saving $500-800 in labor.

Good luck

I forgot to add that gas mileage increased 1-2 MPG with new knock sensors, new airfilter and new fuel filter.

I bet your cabin filters need replacement too.

All always done at once annually.

bullittandy wrote:This certainly applies to a 97 and likely through 01. Sory no pics (see farfetched writeup)Items to be removed:-Engine cover-Engine fan-Alternator (lower mounting nut had to be taped to case to hold it on during assembly)-Upper radiator hose-Aluminum radiator neck/hose (attached to above)-4 inch rubber hose under plenum (attached to Y-fitting) This hose likely has to be cut off, I purchased it from the dealer, $13 but it could be matched at autoparts store-Knock sensors-obviously, they look difficult to get to but came out with a 1/4 socket wrench-wiring harness The new knock sensors are difficult to get in (starting the bolts) but truthfully it could be done in 2 hours the second time around

Moral of the story:97+ Q owners with a minimum of mechanical ability (brake job ability) can make this repair, saving $500-800 in labor.

Good luck

Its true! I did it again today in two hours. Replacing the K/S only on my 99 Q45T -no harness- and it was 2 hours nearly to the minute. Same observations as above except that I KNEW it could be done and that provides for alot of gumption when you can't reach a bolt/start a bolt/get stuck.

Observation=I do not think you need to replace the K/S harness on the 97+ cars. I have inspected three 97+ cars and none of them needed a newharness for the K/S. This combine with the poll on the condition of the under plenum hoses and the Y33 guys noted that their hoses were supple after 10 years. There must be a design change that drastically lowers the heat under the plenum on the Y33. I bought a set of K/S off Ebay for $100 shipped.

bullittandy wrote:
Observation=I do not think you need to replace the K/S harness on the 97+ cars. I have inspected three 97+ cars and none of them needed a newharness for the K/S. This combine with the poll on the condition of the under plenum hoses and the Y33 guys noted that their hoses were supple after 10 years. There must be a design change that drastically lowers the heat under the plenum on the Y33. I bought a set of K/S off Ebay for $100 shipped.

good to hear. still haven't had to do the fgy33 yet. 995xx miles. were you able to inspect the harness connectors close up? your ks deal sounds good--were those for white box oem Nissan parts? if so, please reveal your source.....

They were not OEM parts but do come with a 5 year warranty. I searched for "infiniti knock sensor" but can't remember the seller. I thought I'd risk non-OEM since these are not specific to the Q45 and cover all kinds of Nissan/Infiniti models and so there is an incentive to reproduce them in the aftermarket. I was not able to closely inspect the harness but on my 97 on which the harness was replaced it was in fine shape and my current 97 parts car harness was also in good condition.

Thought I'd update this with info that the eBay knock sensors were no good. They were the aftermarket brand. Bought "genuine" Nissan K/S and all is good.

-A

bullittandy wrote:Thought I'd update this with info that the eBay knock sensors were no good. They were the aftermarket brand. Bought "genuine" Nissan K/S and all is good.

-A

Thank you for the update, Andy. That is valuable information. So many scammers on eBay.

Thanks for the info-- I'm replacing my KSs today AFTER I test the new Nissan KSs off eBay (deuschpartsusa (sp?)). $45 ea + $5 shipping.

'99 Q45. Only a few simple problems in 160k miles, all this year-- MAF Sensor, Fuel Pressure Regulator, Knock Sensor (left bank), and dirty Throttle Body. What a car! But I'm sure I have more "deferred maintenance" to catch up on. I'm surprised none of the coils or injectors have gone bad, yet.

Now have a multimeter and scanner to check codes and live data. Wife has new car, and I'll keep the Q-- mostly due to what I've learned in about a month on this forum, and with the FSM obtained thru a link posted here.

Jim

Just wanted to bump this...Great info Andy! Now I will know for sure that I will not purchase the aftermarket KS. I saw the oem part was being sold by deuschpartsusa. The ks that is bad is the Bank 1 sensor 1 but it only makes sense to change both of them so they can last atleast another 100k! I'm excited to see how my car will ride after the replacement because my car is sluggish right now...and pulling a hill..ugh!

It is very helpful to have a skinny 10 year old son with long arms available when replacing the KS's. He got the screws started and saved me from a meltdown!

NightRiderQ45 wrote:I saw the oem part was being sold by deuschpartsusa.

Deutsche Parts USA

Then again, not everybody's happy with them...



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Modified by Skibane at 1:45 AM 9/29/2009

I tried to read that site and I had to be a member...so that isn't any help. I'll try to Google the company.

Did you (or Jim or Andy or anyone...) purchase the KS from Duetsche Parts? If so, what was your experience? I may need to replace mine soon but this company is questionable... http://www.bbb.org/new-york-ci...01704/

Thanks, Steve

Usually if the BBB has them rated at an F then you should really stay away. As far as I know not many people complain to the BBB or vise versa.

Just get them from Infiniti Of Scottsdale.