What are the oe plugs for my 99 gs300, are they platinum or iridium and how hard/easy is the install, do I have to remove anything to change the plug. Where can i get the plugs, any advice would be greatly appreciated.

 

I believe the 99 GS300 comes with iridium plugs. You can order them from 'www.l-tunedparts.com' from Carson Toyota ( one of our vendor).
You have to remove the intake tube, disconnect the connectors around the throttle body, remove throttle cable. On the back side of the throttle body, you will see one cooler line, block it with vise grip before remove the line.
Remove 4 12mm nuts that hold the bracket, then remove 3 more 12 mm nuts that hold the throttle body.
Carefully slide out the TB until it's clear the long stud.
Then remove 3 12 mm bolts that hold the rubber insulator ( the long stud screw in this rubber piece).
You will to remove a few 10mm bolts that hold the coil harness and 3 more 10mm bolts that hold the coil packs.
I recommend taking a lot pictures with your digicam on every step, this way you can go back and look at the picture if you forget something while re-install it back together.