Ej207 jdm motor rough idle?

I have a 2002 subaru wrx with a sti swap. My engine ej207 idles rough from 2000 rpm before dropping to 500 rpm and surging back up to 2000rpm. or:I ha

I have a 2002 subaru wrx with a sti swap. My engine ej207 idles rough from 2000 rpm before dropping to 500 rpm and surging back up to 2000rpm.

or:I have a 2002 subaru wrx with a sti swap. My engine ej207 idles rough from 2000 rpm before dropping to 500 rpm and surging back up to 2000rpm.

Tags:engine,2000,