dc header got left in rain has a good bit of rust, what is best way to get it off?

 

stainless? - https://honda-tech.com/zerothread?id=1563439

standard steel - sand off rust, spray area with header paint.

 

mine is ceramic, would that still work?

 

the ceramic coating should stop rust, unless it's been scratched or damaged in some way.

does a magnet stick to it?
standard steel it does, stainless it doesn't.

chances are it's standard steel, wipe it down, lightly sand it and spary with the header paint.

 

yep magnet sticks. I'll try what you said.