knock sensor relocation?

[ticker]

Found this link on Nissanhelp.com

http://x.nissanhelp.com/forums/pathfinder/...relocation.html

 

I've been getting a CEL for a while now and am pretty sure its the Knock sensor. I tried to run new grounds as posted in another post but after a few thousand miles it came back on. I decided to go for it and replace the knock sensor. I ordered one and two weeks ago set out to change it. I got as far as getting the upper manifold off except for one pesky hose in the way back that I could not freaking get to when I realized that I still needed to take off the lower part of the manifold too to get to the KS. F'in Hynes manual makes it sound so simple-NOT At this point I was pretty freaked out that I had unbolted and unhooked so many things from my more or less running fine engine, so I put it all back together and called it a day.

Since then I all cleaned the connections that I can get to and so far the CEL has stayed off but I'm assuming that it will be back. I'm intrigued by the possibility of relocating the Knock Sensor and the local Nissan dealer has the harness called for in the write up for $22.

 

Thoughts, opinions on this procedure?

[02silverpathy]

I would totally spend the effort to move it, not for the one time escape of intake manifold removal, but for future replacement all together! Those ECU's most definately adjust timing as much as possible based off of the KS working so swap it or move it.

 

PS. I had found THIS ARTICLE and was impressed with the overall idea, it was something I never really considered!

Edited October 17, 2009 by 02silverpathy

[BowTied]

you were so close!!!

 

I can understand your frustration though.

Edited October 18, 2009 by BowTied

[shift220]

I took a quick look and it looks like a good easy fix. The only thing I don't like is relocating the sensor to a different spot then the ECM is calibrated for. It will read slightly different then the stock position and may or may not be more or less sensitive to knocking. But if the stock one is mounted on the intake manifold somewhere (I'm not sure?) then this should be fine.

 

Now if your engine wasn't naturally aspirated, then I'd be a little more cautious.

[ticker]

you were so close!!!

I can understand your frustration though.

I know, but all I could think of was not being able to get it back together or busting something important and I wigged out. I really have no mechanical training, self taught through trial and error, and I usually mess something up the first time around and this just seemed like there were too many potential things to screw up.

 

 

 

I took a quick look and it looks like a good easy fix. The only thing I don't like is relocating the sensor to a different spot then the ECM is calibrated for. It will read slightly different then the stock position and may or may not be more or less sensitive to knocking. But if the stock one is mounted on the intake manifold somewhere (I'm not sure?) then this should be fine.

 

Now if your engine wasn't naturally aspirated, then I'd be a little more cautious.

The KS is under the lower intake manifold, necessitating the removal of both upper and lower manifolds and the unhooking of countless hoses, connections, and wires.

 

As far as not calibrated for that spot I hear you. The engineers obviously put it there for a reason. They just neglected to contemplate how that placement would make the cost of replacing a $60 part that is held by one bolt ridiculously difficult not to mention expensive. I'm willing to take the risk. I already have the KS and another couple bucks to get it done seems worth it. It seems like it can be reversed if necessary.

[carwilef7]

Not sure about '98s, but for 97 it's supposedly a non-issue. My KS is apparently dead, and the ECM stores a code for it, but it doesn't turn on the CEL. FSM says it normally has no bearing on settings unless you're revved way too high anyway. :02:

[ticker]

Not sure about '98s, but for 97 it's supposedly a non-issue. My KS is apparently dead, and the ECM stores a code for it, but it doesn't turn on the CEL. FSM says it normally has no bearing on settings unless you're revved way too high anyway. :02:

 

That seems odd, no? What purpose does it serve if it doesn't do anything? I honestly can't say that I could pinpoint the pathy performing differently since this happened, but the CEL being on is killing me though. I can't stand having it lit up, don't know if its OCD or what but I must find a soilution.

[carwilef7]

It's not so odd when you consider the money Nissan might make if this part fails just past warranty - what with removing the intake and all that it entails. Planned obsolescence.

 

Here's what I did, but for a different reason -

 

I kept getting a CEL light for R catalyst deficiency. Doesn't matter for safety inspection where I live - but, like you, I hate looking at the light, and I'll be damned if I'm gonna pay 500 or more bucks to replace a cat just to turn off the light.

 

Do this - trace out your CEL circuit - if it's like mine, it's on an orange wire (one of several orange ones) going into the ECM near the middle of the plug. I snipped the wire and spliced in a SPST switch so I can flip it on if the truck starts acting weird, but I usually leave it off so I don't have to put up w/ the CEL.

 

Be advised though - if you have to have your OBDII working for inspection, you will fail - also, you might be fined for tampering - so be sure you can get away with it before doing it.

Edited October 19, 2009 by carwilef7

[02silverpathy]

That sensor totally works, anything newer than 96 or that has OBDII uses the knock sensor to tell it how the engine is firing or knocking on the gas. It does not need to turn the light on as it could & does easily run with a broken knock sensor...it retards timing to a "safe " position so that minimal engine damage is done.

 

The engineers would put the sensor there so that any grade of gas could be used and not damage the engine. Here in the states we are lucky to have such good quality of fuels....this is also the reason so many country's did not get the 3.5 in the R50...grade, quality, and availability.

 

The article that I posted shows a SC Frontier at least "feeling" a difference after swapping his KS to a new location....the butt dyno is always good for 5 HP returns whether gain or restoring factory power is negligable, the truck ran better.

 

I had a new one put on my 98 and the SAFC II that I had wired in mine showed an average of less knocks...if I still had the truck I would definately re locate it to a new place on the block , since I know I will use good quality of gas. I do not use grocery store gas, or sheetz gas in my path...or anything that has an intake or other modifications...I perfer Shell or BP but there are others that provide good refined fuels also.

 

$.02

[ticker]

not sure if anyone would no the answer but here goes. In the article on Nissanhelp.com it says you need a Maxima Wire harness (cheaper and only has the necessary wires). But it says nothing about the type of KS so I assumed the pathy one I already bought would be fine. On the Frontier Boards it says need the maxima harness and KS. It's my understanding that the pathy and the maxima share the same VG33 engine so why would the KS be different?