So I am about to Tune Up my GS 400. I have searched through the Forum, I am just seeing if anyone has any other suggestions, and confirming that I am taking care of everything that can possibly be taken care of.

Here are the steps I am taking so far in the Tune Up:
New Spark Plugs
Clean the Intake Air Filter
Clean the Throttle Body
Clean the MAF
Sea Foam

Are there any other lesser known methods that I missed to get the Engine Running at its Peak Performance on a GS 400.

 

Change your fluids and i'd check LBJ's and Tie Rods while you're down there.

 

Thanks for the heads up on the fluids. I actually just received new LBJ's and Tie Rods in the mail. The only problem is that I ordered Beck Arnley Tie Rods and since they are a distributor, I was distributed Tie Rods that are 2 separate brands.