Hi exbboy10

sorry to hear that you have same issues.. mine was intermittent, but does come on often now, since only one side comes on my mechanic really believes its the sensor so i am going to get that changed.

have you tried running a fuel cleaner?

and yes looks like alot of stuff needs to be opened for it to come out unfortunately

from what i have read, people that have issues with these, once they are changed the car performs really well (as you have probably noticed some hesitation)

 

Update: Got the Knock sensors changed today, car seems to be running very smoothly, throttle feels much more sensitive/responsive. will keep everyone posted.

Taking the intake manifold off was not hard, just requires a lot of things on top to be disconnected (if i was to do it myself next time i would be able to within max 2).. throttle body disconnected, and hoses above it on manifold pulled off, air intake box with hoses detached. the housing holding the chunk of wire is mounted to the intake so need to remove that.. and small brackets here and there.. OH and fuel line connected to manifold top right corner... manifold needed to be pulled out toward the passenger side of car then up (you will need two people for this process)

 

Interesting, so that's how it looks inside. I'm surprised at how much rust is down in there though.

 

Yes the starter is there too.. but yeah if you look closely the rust is just on that one pipe and the main body of starter, maybe from car wash water, dono.. rest is just dirt/sand. So engine itself is very clean which i was happy to hear, no leaks or anything either I wish I had the chance to wipe the dirt down!

 

Does anyone have any idea what it would or should cost a shop to replace the knock sensor?

 

2 hours labor max i would say after watching my knock sensors get done.

 

I have Sc430 had the spark plugs changed, had a coil changed out. Car ran great. Next day questioned the spark plugs they used.Due to it was dragging.. They did not use the ones I asked. So they put the DENSO in. NOT ONLY did they do this they use SEAFOAM in my car on an empty tank in which I am still driving that tank of gas out. Car had power but today it threw a P0330. And its not as powerful as the car should be. Mechanic says its misfiring bring it back when the light comes back on the VSC. I asked what the code was he said it meant it was a random misfire. SOOO advice before I have to go to Lexus .. what is going on

 

 

I need some HELP!
I am tackling the replacement of both knock sensors.
So far It has taken me about an hour to disconnect all the hoses and electrical connectors.
Not too bad-- word of caution: hoses are brittle and so are connectors, they will break so be very careful and patient when tugging on them.
I think i'm at the last hose that needs to be disconnected before I can remove the top part of the engine.
In the picture you will see a hose that looks to be metal, do you think this is a pressurized hose??? and if it is how do I disconnect it without getting gas all over the place???
Thanks for any assistance!

 

 

Bgw70- Thank you for your help!
I'm glad you mentioned the specific "line wrenches", I don't have them so a trip to the tool store is always fun.
The car has not been driven for a few days and I opened the gas cap for what its worth.

 

I'm not a mechanic, but have been taking my 1992 sc400 and 2002 sc430 apart for repairs and maintenance for the past 15 years, so I feel very comfortable doing it.
getting to the knock sensors was not difficult using the forum help. It took me a little longer than expected because of the gas line you see above in the picture.
even with the new line wrenches I bought, and a heavy spraying of WD40, it was difficult taking it apart. I had to get creative and buy a set of crowfoot flare nut wrenches and use a curved jaw locking pliers to loosen it. That took the longest because...it is a metal fuel line and it would be a huge job to replace it. (be very careful).
Would I recommend taking on the project, Yes!
Good luck if you take it on!

 

Update:
I have been running the car daily for a few weeks now and everything looks and feels great!
The only problem was a P0141 code---O2 sensor heater circuit bank 1 sensor 2
Not sure if it was because I ran the car with the bad knock sensors for about 2 months or a coincidence.

 

We had an RX 300 a couple years ago with one bad knock sensor. On this forum for that car was a description of how to find the place in the harness to splice the two knock sensor wires together so the ECM thought both were working. The place was in the harness behind the glove box.

Fixed the problem easily and was just a bit of wiring without taking the motor apart.

 

Hey guys I'm doing the knock sensor and harness job I have the manifold off and replaced the sensors but can't find where the hell the harness connector end is can anyone help please. Thanks in advance.