OK, here's my thing. I've got a Greddy TI-C dual exhaust and AEMv2 CAI installed already on my F20C. I wanna install a Megan racing test pipe and header but I dont wanna do my ECU. I've had previous problems on old Honda's I've owned with ECU mods and plus I dont wanna mess up my S2K (Its my love!!!) Will my stock ECU learn all the changes that I've done? The car will run lean? Will it be a problem to run lean? Cause damage? Please help!!!

 

No it will change the Air/Fuel mixture in Wide Open Throttle (WOT)

You will need to get something to add fuel and adjust accordingly.

I think Vafc will add fuel, I know it will lean just not sure about the other way around.

 

sorry buddy, you're out of luck. either install the parts and tune, or leave them off.

see other tuning threads for more info. it's exhausting consistently typing all this out.

and the s2k isn't like "other" hondas. get a legit tuning device with a capable tuner and you will be fine.

problems amongst people that have tuned appropriately using a method i like to call "the right way" are very minimal.