Y33: problems with Knock Sensor

[infiniti97_owner]

Hello everyone,I'm a newbie to this forum. Had a quick question...I own a 97 Q45, couple of weeks back changed the spark plugs at firestone, after driving around for 500 miles started getting knocking.I took it to Autozone, their diagnostic shows that the knock sensor has gone bad. My question ..... is this related to my changing the spark plugs... i had taken it to Firestone but they quickly ruled any relationship..Also can anyone suggest any place where i can find a decent priced replacement sensor.

TIAcheers & Happy New Year

[pnanda16]

Hi and welcome to the club. I own a 97Q45 as well and recently some events have made me read and talk to many people related to knock sensor, Throttle position sensor etc.

First, you need to tell us about your car, how old, miles, how about maintenance, how long have you owned it etc, these can help.

About knock sensor relation to spark plugs, I will let the experts answer. But I know that the Y33s (97-01Qs) have 2 knock sensors (one in intake, one in exhaust?). Both are idential. Joe Tsensky (sorry for the bad spelling!) at Scottsdale Infiniti is the parts contant for this forum, he is a great guy and can hook you up with whatever you want. You can search for him in this forum. I think the knock sensor costs $126.xx each and I think the labor is going to be a lot (4-6hours), but you can find that from local mechanics.

Let me know how it progresses. I have also posted a recent thread (search under pnanda16) and see if there are any similarities.

FInally, there is a lot of knowlege already available and doing a 'search' is going to give you tons of useful info.

cheersPhal97 Q45, 143K miles

[maxnix]

I will let the experts answer. But I know that the Y33s (97-01Qs) have 2 knock sensors (one in intake, one in exhaust?).

One on each bank of cylinders.

Please tell us Firestone used the OEM specified NGK plugs.

[elwesso]

If your knock sensors are determined bad by pulling your DTCs they arent the cause of the detonation. If you didnt use OEM NGK PFR5G-11 plugs all bets are off! When the ECU throws a KS code it retards the timing so much you probably wont detonate under 95% of conditions.

If your ECU isnt throwing a code, then its pretty safe to say your KS are working. If they used too hot of a plug, it could cause the motor to detonate and seeing you live in TX this is a factor....

However you do indicate that the KS is bad, so im thinking that the knocking has no relation to the KS (ironically). Like I said, when the KS go bad the ECU adds fuel and retards timing so much that its basically impossible for the car to knock assuming all else is good.

let us know what plugs went in!

[infiniti97_owner]

Hello Folks, Thanks for the replies.I talked to Firestone, they put in Bosch Platinum plugs (4301).Appreciate all your help.

[Q45tech]

SO SO MANY recent Texas problems since the conversion to 10% Ethanol from MTBE.

[infiniti97_owner]

Hi PhalI have about 95K miles on it. I have had it for 2.5 years now, i got it with 69K miles on it and was told that the 60k was done on it. All my regular maintenance was done at the infiniti dealer, this is the first time i took it to firestone for non-tire related issue.Spark Plugs were changed as a maintenance, i was not having a problem before with anything- the car was running smooth with no issues.Please let me know if you need more info. Thanks, MK

[infiniti97_owner]

I was on a roadtrip right after i changed the plugs.

I filled up (premium 93) at a gas station in Oklahoma and started noticing this problem almost instantaneously.So not sure whats going on.

[maxnix]

Still not telling us which plugs were installed.

Try a can or twoo of ISO-HEET (NOT HEET!).

How long since you changed air and fuel filters?

Only Houston and DFW metropolitan areas using ethanol so far.

[infiniti97_owner]

Hii think i already mentioned that in a previous post.... unless i'm missing something.

Firestone used BOSCh Platinum Plugs (4301)

TIA

[infiniti97_owner]

The air filter was changed couple of weeks back. I have not changed the fuel filter since i have owned (approx 20K Miles).

Thanks

[elwesso]

nope, you mentioned it.... Someone didnt read the post!

Those bosch's are a BAD BAD BAD idea. Id think they could have caused the problem, but they are known to FAIL in Nissan V8's and id get those replaced for proper spark plugs immediately. For the best price, call Joe at everything infiniti, his contact info is in my sig.

[infiniti97_owner]

Hi Wes,Thanks for the reply.So do you think my problems are related to the Spark Plugs, or it could be something totally different.Also could you suggest some appropriate spark plugs ?

thanks again

[elwesso]

Youll want to get the PFR5G-11 OEM NGK plugs Call Joe at Infiniti of Scottsdale (contact info is in my sig), tell him Wes sent you.... He seriously has the best prices on OEM plugs, most places charge between 9-11/plug, and I think his set is something like $65/set....

I dont necessarily want to say your problems are because of the plugs, but this is soemthing we HAVE to rule out, because leaving those plugs in there will MOST LIKELY cause serious engine damage!