Hello, few weeks ago i finally replaced a correct 02 sensor that was bugging me for over a month. long story with bad misinformation from autozone salesman on that. As soon as 1 thing got fixed my car started misfiring so first thing i did was replace the spark plugs and that seem to have solved the misfiring but other thing came up i did a test on obd2 reader and got several codes (P2198 p0333 p0328 p0159 p2192) i went ahead and reset the codes via the computer but as soon as i started the engine again the codes came baack up but only these 4 (p0328 Knock Sensor 1 Circuit High Input (Bank 1 Or Single Sensor) p0333 (Knock Sensor 2 Circuit High Input (Bank 2) p0328 Knock Sensor 1 Circuit High Input (Bank 1 Or Single Sensor) p0333 (Knock Sensor 2 Circuit High Input (Bank 2). Now that i wrote this i realize that two of the four codes are the same but for some reason the code reader gave me 4 codes 2 of them being the same. Any advice on what i can check or do to fix this? also if I need to replace the knock sensors, is there a diagram somewhere that i can find to see the location of these sensors? Thank You Mr.You Who Reading This

 

I would look to see if there are any suspicious looking Toyota Camrys around.

 

It is too much work to replace the original knock sensor. I have 2004 RX330 and P0328 for bank1 knock sensor with check engine light. One week ago, I used aftermarket Toyota /Lexus knock sensor, replace the original one, mounted it outside engine with required torque. It works so far. No more check engine light. Car runs normal. Relocation may not be the absolute correct fix. Since my car is 15 years old and has 160K + mile, my DIY repair costs me next to nothing, I do it anyway and passed state inspection.

Have you try to disconnect the harness and reconnect them again? After I cut off my bank1 knock sensor wires I still got the same P0328. May be yours are loose connection.
Have you get a quote from Lexus dealer for repair?

 

These 2006 GS300 have known issue with carbon buildup, so much so several years ago lexus offered free engine rebuilds for people that have this problem.

To me it doesnt sound like you have a knock sensor issue. If anything to me it sounds like the knock sensor is working. When carbon clogs your intake valves, your basically choking the engine. The injectors are firing, increasing the fuel but with less air in the combustion, the o2 sensors are showing a rich fuel mixture. When the air/fuel mixture is so bad the engine can no longer compensate and the engine knocks, and you get misfire and poor performance.

Option 1: To fully clean the engine you will need to remove it and do a full rebuild. That way you can replace the piston rings that are probably carbon locked. This is the right way!

Option 2: You can remove and clean the intake manifold, and the plenum. This will give you access to the intake manifolds and the intake runners. With long stiff brushes and chemicals like seafoam or berrymans parts cleaner. Scrub and clean the insides of the cylinder head. Or you can take your car to a mini/bmw mechanic that does walnut blasting, as carbon issue plaque minis aswell and they found a way to clean it with a sand blaster that sprays walnuts and a vacuum cleaner.

Option 3: This is the least effective but will help you. Its to warm up the car really good. Buy 2 cans of regular seafoam the kind you poor. Pop off the engine cover, there should be a plugged vaccum block on the intake manifold. Remove that, and find a vacuum line that will fit over that, thats atleast a foot long. Pour 1/3 seafoam into a coffee much and with the engine running and hot let the engine vacuum in the hose gently suck the seafoam to the point the car almost wants to stall, but dont let it suck to much. Once that 1/3 is done turn off the car and let the chemical soak into the carbon. Keep repeating this until you finish both cans. But I must warn you, your neighbors will not like you, as this will create a smoke show