Great write up. Thanks. Will be tackling this soon, just ordered denso Plugs and 3 rear coil, figured might as well replace the rear sine I will be taking off everything.

 

I keep hearing the three rear plugs can be replaced without removing the manifold, although, it is a job for those with good hands, good tools, experience and patience. I believe it entails removing some parts on the firewall or cowling. There are some YouTube videos on this, but I haven't watched as my ES is at just 77K miles.

I was able to do this on my wife's 1997 Avalon. The layout is very similar, but not identical. Has anyone done this job on an ES without removing the manifold?

 

I saw that as well for 5th and 6th gen ES. Most likely the route I will take, but if I am having trouble, will than take off the manifold.

 

Yes, there is the cowl/wiper method. By removing the body panel that is over the plugs, you can avoid removing the intake plenum. I’ve replaced the plugs twice via the intake method and will continue to use that method now that I know what to do. However, I completely understand wanting a method that does not involve removing engine parts. If you mess something up like drop a bolt into the engine, you’re looking at an expensive repair bill. If you break something with the cowl method, the car remains drivable.

BTW, I think the 120k plug replacement recommendation by Lexus is way too much. I replaced the plugs at about 115k the first time and the gap was way too much - the center electrode was worn down significantly. This taxes the ignition system and I have no doubt this has contributed to having to replace 3/6 ignition coils by 200K. A 4th one recently went out- but engine is approaching 250K. I recommend replacing the plugs by 80K. I replaced with Denso Long Life iridiums.

 

I ended up doing it last night, no way in hell I was going to take out the plugs without removing the intake. Tried the easy route but ended up going the intake route which was not bad at all IMO. Tough part for me was two 12mm on the left side of the manifold otherwise it wasn’t bad. Replaced it with denso plugs and coils.