Use this DIY Tutorial to change the Spark Plugs on a Second Generation Lexus GS 300 (1998-2005 Lexus GS300)

Works For:
1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 Lexus GS 300 Models

Source:  ClubLexus

To change your plugs you will only need basic hand tools such as a socket wrench and some extensions and a set of allen wrenches. It would help to have a swivel extension for your socket wrench as well because the last plug is in an awkward position.

Enjoys the pictures.

Next, remove these screws from the throttle body in order to lossen it enough to slide it out of the way.

Look under the front of the throttle body and you will see five more screws. Three of them will hold the throttle body and two will hold a bracket under it. Remove all of them. As a side note, the bolt that is in the center of this picture needs to be screwed all of the way out or you will not be able to slide the throttle body out of the way. Trust me, this will save you some time and headaches.

Now you need to twist the throttle cable cam back to release the cable

n this picture, you see that the throttle body has been slid forward so you can see the plug wires and the coil packs. The little gold screw on the left of the picture will need to be removed in order to get the coil pack out. By the way, coil pack that is directly under the throttle body was a b@$#$ to remove and put back in place. I probaly wasted 15 minutes on this one alone. Once you replace all of the plugs, just put everything back the way you took it out.

The whole job took about an hour and 45 minutes from start to finish. This was my first time doing and this is yet another job that Lexus can’t overcharge me for. I hope this writeup helps everyone who has been wanting to do do job but was afriad of the labor involved. Let me know if you have any questions.