i have an 03 evo 8 the current mods are hks turbo back exhaust, hks fmic, hks ssq, oil catch can, 264 cams, ported head, 650cc injectors, electric boost controller, AMS EMS, and a few others. I was thinking about getting an o2 dump... what is your guys opinion on that? also would i have to get a retune after i install the o2 dump? thanks

 

yes you will need a retune after o2 dump otherwise you will get alot of knock. i had 0 knock before and 5 counts after. retuned and no more knock. quicker spool and less boost taper..well at least on my car. every car is different.

 

Please search and read the massive O2 dump thread. Countless posts on before and after numbers. Mine included.