Over past week, had a knock sensor go out on me (2001 w/ 240k on the clock). Removed the manifold and figured I would replace the starter as well.

Knock sensor was easy to replace, need a 27mm for the sensor itself, but the starter is a whole bag of pain/. The starter is located under the manifold in the V of the engine. There are 2 bolts (17mm) on the back side of the engine that you can barely access with a 3ft extension if you drop the transmission mount (4 bolts).

Put everything back together with the "new" refurbished starter. Started the car and it made a horrible metal whining sound. Took everything apart again to find the starter gear was 1/4 inch too long.

If you DIY your starter, make sure the starter gear is the same size as your original. Turns out the starter I received was made for a sc430 instead of the ls430 as requested.

BONUS TIP: When re-installing the intake manifold/plenum, be very careful with your radiator temp sensor. Snapped the connector off for a $120 lesson..

 

Did you get a CEL for the knock sensor? Were you experiencing any symptoms with the car?

 

Yes, had a CEL for the knock sensor. I think it was p0325. I figured since I already took everything apart I should just replace both sensors. Lexus of SA was approx 170 each. I think rockauto has alternatives for ~120.

The car's throttle was delayed, revs climbed slowly when the "WOT". I had no precursor symptoms. Was about half way through a tank when the car decided to limp on a residential street.