So had similar issues with other sc430 owners.. I'm driving an 03 with 200k miles.. went through the deep dark rabbit hole of the vsc and vsc off/tpms/chk engine light/limp mode/etc.. anyone who came to this forum and had these issues knows my struggle and I'm not going to get deep in all of that theres plenty of posts on those things.

Ok, so I'm confident in that when I replace my two knock sensors that this will correct the last of my issues. Here is my dilemma, I bought the sensors and have them and I am going to put them in next week. With that said, I'm doing the labor and my manifold I'll be removing either way. What I'm on the fence about is my starter, if I'm there I should replace starter as well being how lexus put it in such a convenient spot. Now with having an sc430 with sensor issues and the problems we encounter more so with the earlier years of this vehicle.. I spoke to other sc430 owners who their car eats starters at an insane pace and have checked and troubleshooted just to be confused and replace starter yet again.

One gentlemen in particular was in the same boat as me and went ahead and replaced starter with I believe a denso and went got the nicest spec one he could, nice and spendy.. figured like me hey if I'm there might as well do all the maint, he bought the expensive gold little oem knock sensors and starter and issue came back! But wait theres more, and now he has starter issues and since replaced starter with another one and now still having starter issues now which he never had before!

I am not the original owner so do not know full scope of service that has been done to the vehicle but other than my current issue shes start and maintained well, most big stuff records for from lexus..whole timing done at 188k miles..

Any insight? Replace the sensors and see from there? Do the starter while I'm there as well? In most things In life you get what you pay for but i have always bought cheap aftermarket sensors for cars when replacing things as i have found some of these parts are equally made as well and for a fraction of the price...

 

I haven't heard of SC430s eating starters. I believe that it is a fairly rare failure.