Marklouis

So I broke down and did this process last weekend, this is for the 460. Very easy and took no time at all. Unplugged the battery first before I did anything else. 4 10mm bolts on the front, unplug the throttle body harness, and also 2 small coolant hoses are connected on the bottom back of the throttle body as a run through - be sure and make sure engine is totally cooled down before removing those small hoses, and there is a pressure relief screw located at the top of the main radiator where the top coolant hose connects to.

Be warned though after the cleaning proccess combined with the battery unplugged for a length of time your GS will possibly run in a safe mode for a day or two, the throttle response lags and power seems cut down, but all the parameters of the system eventually returns to normal. Mine behaved this way.

Marklouis

MAF sensor was a piece of cake also. Just 2 screws located at the back of the airfilter box. Be sure and use MAF sensor cleaner recommended for the brand you have, mine was Toyota Denso so the CRC MAF Sensor cleaner I used was safe. Notice the MAF housing has sensors in 2 different locations, at the base and inside the tube.

Went ahead and polished up the headlights while I was at it with 3M perfect it III compound.

Othic

Here's the process for the GS/IS V6

Remove side engine cover (already removed in picture)
Loosen the 10mm clamps and remove the PCV tube (already removed in picture)


Remove the 4 10mm bolts on the throttle body and proceed to clean the throttle body.


This picture just shows the back side of the throttle body


Picture of one of the intake ports. This engine had a rebuild done not too long ago. I forgot how long ago but it was less than 2 years

Lexo11

Did you replace the gasket / sealer when you removed the tb?

Also, does the internal medal plate open freely. Can we just push it open or is it electronically limited?

gr8fulRed

good questions. I attempted to clean my throttle body the other day but stopped. I was reading that if you force the plate open that you would have to reprogram your ecu or something and that it's better to have someone else in the car push the accelerator to open it (with motor off). Well, I tried that and not only did it NOT open...but it would start making a light buzzing noise when I applied some manual pressure to the plate. I cleaned the front opening, but not the back and not much else as I was afraid i would cause a bigger problem.

Othic

The throttle plate will rotate 90 degrees freely when opened. There's no reprograming and you wont damage it as long as you don't try to force it open passed its capabilities. I was performing a recall on this specific car and the recall doesn't supply a throttle body gasket. I've never had one leak before.

Lexo11

Someone had mentioned that it would be good to just replace the gasket since it is already unscrewed. Wasn't sure if it would really matter or not. I assumed it may be worn out might as well replace it.

NotADood

I'm a Lexus master tech, and have seen plenty of vehicles that will not idle properly with a dirty throttle body due to carbon build up. Especially after the battery has been replaced, and the throttle learn value has been cleared. The vehicles will simply die at idle, and the gas must be held dow partly to keep it running.

Clean the throttle every 30K, anything less is overkill.

Brabusx2

thanks guys!

i will do new plugs and TB cleaning sometime next week!

Philskie1

Yes, if you remove the throttle body you will need to replace the gasket. Is the cleaning important, YES. Prob every 60k. The throttle body flap will sit against the are closure wall and will have carbon buildup and not be seated perfectly which will affect idle. Some will barely notice others will notice greatly. The throttle body does not need to be removed and clean rag and couple of sprays of TB cleaner on the rag will remove the garbage on the flap, walls and seating area. To open the flap push gently with your finger. 1st time 15-40 mins and save yourself $300 in 2024. The Car Care Nut has a good video on doing this, youtube.