Relatively new to this forum although I have had my evo viii for a little over a year. I keep pulling an iac code and it's causing bogging issues (at idle obviously). I replaced it and it still having the issue. Not really sure why to do at this point. Could it be a tuning issue? Any suggestions will help. Thanks.

Mods include: cams, intake, straight exhaust, boost at 21lbs (was at 23-25 but injectors are at 98%) shep rebuilt trans.