I bought this 2002 sc430 with 82k miles 6 months ago have only used 6 times and have driven less than 100 miles mainly standing outside under cover.

All of sudden have slow acceleration and check engine light

had the codes read from auto zone it says both knock sensors bad

can someone tell me where they are located on the sc430 and is it easy to replace

many thanks for your help and advice

 

I wonder if you are experiencing condensation your gas. Maybe try adding a fuel preservative and top it off with the highest octane gas you can find. Or drain the tank. Disconnect the battery for a 1/2 hr. or so and try driving it again. Just a guess....

 

They are located under the intake manifold. It's simular to the process required to get to the starter. It's big bucks on labor. Usually a 1100+ bill from the dealership to replace both. I just had to replace mine and had to pay 900. I got the same check engine like you and everything, but I have 32K more miles than you on my GS. Limp mode time. No reading for 2000-5600rpms.