my 45k service is due soon on a my00,which spark plug's are the best i have a jr panel,ninja backbox and de-cat centre,are the denso ik20 any good?

 

bttp

 

I dont know for impreza, but I put denso iridium on my fazer600 (03) and I see changes (i didnt expect anything), now its can do 220 where before can do max. 200. Top spd is not changed, maybe 5kmh (235-240kmh).

Sorry for language.

 

I use PFR6B from www.sparkplugs.co.uk

Tim.
MY99 full de-cat, k&n ind kit etc.