I used to be an STi owner and aside from the vape pen at indoctrination, you were told by every Subaru owner to get an access port even if you were staying stock. As a quick rundown the accessport is able to monitor, tune, change maps, check/clear codes, and does this all by plugging into your OBD-2 port. I've attached a picture for those who are not familiar with them but I was wondering why S2000's or Hondas in general do not have this? I know you can get AEM or Hondata but are insanely expensive and intrusive compared to the $500~ plug and play. I'm 100% not taking it lightly, I'm SURE it is difficult but I'm a computer engineering student with a summer internship at Toyota for ECU design (not bragging).

 

2000-2005 ecus are not reflashable. That’s why

 

WRX/STIs have had flash capable ECUs since their introduction in the US. S2000s didn't see that until MY2006 so for most MYs an aftermarket ECU is the only choice for engine management.

That being said, people run OBDII or CAN gauge packs all the time on S2000s. The biggest challenge is that there is not a lot of room to put such things in a S2000 (in a clean way) vs a "regular" car.