[Brian]

Easy advice really..
If in doubt whip 'em out!

Always remove suppression capacitors (look very carefully for those little hidden ones too). Doing the removal at the time of decoder installation will save you later on having to open the body of the loco to do the job and as far as I'm aware most decoders have built in suppression anyway.

I have never seen a loco run badly on DCC once the manufactures caps fitted have been removed but they can act erratically if left in place!

As for inductors; I'd leave them in place as they normally do no harm to the DCC decoder or the loco's DCC operation and if you do remove them, it will in most cases, mean running a wire link to replace each one on the PC board.

 

[Brian]

Again I say... "Get 'em out" to the installer of a decoder.

There is no need for the original suppression capacitors once a decoder has been installed.

Warranties won't be broken and there is no possibility of the original caps causing problems - they've been removed!