for your air filter issue,actually open pod might give you better benefits if you have a heat shield.go for the apexi one if you really want peformance.it has been compared to all the other filters where it gives you the best HP upgrade compared to HKS and ... and it does not have any maintainance worries,like washing it and etc..
you have nothing to worry about your ecu.air filter would give you a better air intake.not really effecting your air-fuel ratio.
you have nothing to worry about your ecu.air filter would give you a better air intake.not really effecting your air-fuel ratio.