Knock sensors on their way out, with supercharger...what else to do while in there?

'00 4Runner Limited 4X4 @ 255k, w/ 2nd Gen Supercharger installed by dealer in '00 @ 800 miles. Newer engine with 100k miles total.

Well, it seems that it's my turn for the dreaded knock sensor replacement. CEL keeps coming on and off, and my power and fuel economy has dropped drastically. Now I'm just wondering what else I should do while I am in there. I'm not sure what maintenance the P/O did to the supercharger, but I will be putting a new nose cone on, when the S/C is pulled. I know it's not necessary to pull the S/C to do that, but I think it will just be easier to do once it's out.

$173.33 for the new nose cone, oil, phelonic drive adapter, fill plug, Loctite gasket eliminator, and fill plug.
NOSE CONE 3.4V6 BLK | Genuine*Toyota | 00602-17620-226

$85.00 for a pair of new, Toyota OEM Denso knock sensors.
Genuine OEM New 89615 12040 Set of 2 Denso Toyota Lexus Knock Sensor | eBay

$29.89 for a new, Toyota OEM knock sensor harness.
82219 07010 Knock Sensor Pigtail Harness 1998 2006 Genuine Toyota Part See Chart | eBay

$80.79 for a new set of Fel-Pro upper and lower intake gaskets.
2000 TOYOTA 4RUNNER 3.4L V6 Intake Manifold Gasket | RockAuto

That's $368.98 total for all of the parts. My 4Runner has been running like a champ up until this, minus the engine replacement. That was the P/O's, mechanics fault. He didn't use a new bolt on the harmonic balancer after replacing the timing belt and water pump. The bolt came out, then detroyed the end of the crankshaft as the harmonic balancer grinded down on it. His fault...my bill. Oh well.

Anyways, is there anything else that I should be changing while I am in there? I'm ready to take her another 250k!! Any input is greatly appreciated, thanks!

My knock sensors also failed about 6 months after supercharger install. Sucks to tear everything down again. I drove around for some time and just kept clearing the code with the scanguage. The only thing I can think of is valve cover gaskets if needed. It would be much easier to do those with everything else already out of the way.

glad to see you have the knock sensor harness on your list. You don't even have to touch it for it to break, if you just look at that thing the wrong way it will break. And as mentioned above, a good time to do the valve cover gaskets if you haven't done them recently.

sn0wrunner said:

glad to see you have the knock sensor harness on your list. You don't even have to touch it for it to break, if you just look at that thing the wrong way it will break. And as mentioned above, a good time to do the valve cover gaskets if you haven't done them recently.

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Lol, that's what I've heard. With the extreme temperatures that harness sees, it's no wonder! No leaky valve cover gaskets yet. The new motor only has 100k on it. Thanks though!

afg10000 said:

My knock sensors also failed about 6 months after supercharger install. Sucks to tear everything down again. I drove around for some time and just kept clearing the code with the scanguage. The only thing I can think of is valve cover gaskets if needed. It would be much easier to do those with everything else already out of the way.

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I should have been more clear. The supercharger was installed at the dealer in 2000, when it only had 800 miles on it. The newer motor doesn't have leaky valve cover gaskets yet. Not worried about that part just yet. Thanks though!

jsukey said:

$173.33 for the new nose cone, oil, phelonic drive adapter, fill plug, Loctite gasket eliminator, and fill plug.
NOSE CONE 3.4V6 BLK | Genuine*Toyota | 00602-17620-226

I paid $228 for mine back before they doubled. Are you sure this is the correct kit? Here's my PN PTR29-35042

$85.00 for a pair of new, Toyota OEM Denso knock sensors.
Genuine OEM New 89615 12040 Set of 2 Denso Toyota Lexus Knock Sensor | eBay

At that price - very suspect. There's a lot of counterfeits on there. Regular price is over $100 each. I would look somewhere else or get some validation from someone on here if they've used this guy or not. But ONLY USE OEM!

Anyways, is there anything else that I should be changing while I am in there? I'm ready to take her another 250k!! Any input is greatly appreciated, thanks!

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Looks good. Take your time, and tape and cover everything. Take pics before you start. Ziplock bags and a sharpie for parts.

Rock_Rat said:

Looks good. Take your time, and tape and cover everything. Take pics before you start. Ziplock bags and a sharpie for parts.

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I will call that company and see what is actually included with that part number. I got the part number off of this guys post when he rebuilt his:
3.4 Supercharger Nose-Drive Replacement - Toyota Tacoma Forum

I was also very suspect of them being that cheap, but it shows the sensors in an OEM Toyota bag with the part numbers.
Genuine OEM New 89615 12040 Set of 2 Denso Toyota Lexus Knock Sensor | eBay

I would have your injectors cleaned, change the spark plugs and VC gaskets, and make sure the timing belt and water pump still look good.

I just did this job on my 4Runner, and since I was due for timing belt, etc, it all happened at once.

You shouldnt need the Fel-Pro upper and lower intake gaskets. I've been reusing mine just fine. Besides - you don't even use the upper one when you have a supercharger!

I'll chime in among the rest - valve cover gaskets and all associated maintenance are worthwhile. Be sure to get new injector O rings as well. Injectors have to be removed while you access the valley of the engine.

I don't feel comfortable reusing old gaskets. Especially in a boosted scenario. I'd rather do it once, and do it right. The supercharger bolts to the lower manifold assembly, so it still requires a gasket. It doesn't require the injectors to be removed to replace the knock sensors, but as cheap as the o-rings are, I will probably go ahead and change them. Valve cover gaskets aren't leaking, so I'll leave those alone for now.

Having done the job twice, the fuel rails need to be removed, hence the o-rings.

The gasket is a metallic gasket - not the typical rubber one you'd expect.

rideexileex said:

Having done the job twice, the fuel rails need to be removed, hence the o-rings.

The gasket is a metallic gasket - not the typical rubber one you'd expect.

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You have to forgive me, I misread another post with detailed pics showing how to replace them. He said that removing the injectors from the plenum wasn't necessary. His upper intake gasket didn't look metallic. I would rather order them and have them, just in case the factory gasket gets damaged. If I don't use it, I can always return it!! Thanks for the info!

I know it was mentioned that I should clean my injectors...what about upgrading them to truly accommodate the supercharger? Any thoughts on that? I'm not running the 7th injector.

Double check the part number for the harness, it is listed for 3.0 not a 3.4

Makitso said:

Double check the part number for the harness, it is listed for 3.0 not a 3.4

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Good catch! I missed that. Many thanks!

Here ya go dude. This was the stuff I ordered. Confirmed it with TheDurk. Everything was great and perfect OEM. No problems.
https://www.amazon.com/gp/product/B00K1MMS9I/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B00KQ3HT2S/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

jsukey said:

You have to forgive me, I misread another post with detailed pics showing how to replace them. He said that removing the injectors from the plenum wasn't necessary. His upper intake gasket didn't look metallic. I would rather order them and have them, just in case the factory gasket gets damaged. If I don't use it, I can always return it!! Thanks for the info!

I know it was mentioned that I should clean my injectors...what about upgrading them to truly accommodate the supercharger? Any thoughts on that? I'm not running the 7th injector.

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Are you running the stock pulley? If so, I would look into the "Free fmu" mod, and you will likely be good-ish. Bigger injectors are good only if you add a piggy-back ecu.

I had the URD 7th injector previously and didn't care for it - I upgraded the 6 injectors to blue top injectors (somewhere around 315? I'd have to double check) with the AEM FIC-6 and AEM UEGO O2 sensor (analog version) and have been so much happier. Tunability is fantastic and I am spot on across the entire map, even in partial throttle. This is all with the 2.1 pulley. I'm happy to ramble on about this in detail if you like, but it snowballs a bit/lot.

Maybe an ignorant suggestion, but why not pop the two rivets that hold the metal plate around the metal heater line. Replace it with some mesh. Master Toyota mechanic told me it was only there to keep rodents out. Seems to me that it also keeps a lot of heat on the sensor wire.