I have been considering either an INJEN or SRT intake system for my '03 GS430...

Are there any issues with normal driving in the rain with these intakes?

I will probably lean towards the INJEN because from what I have read on this forum, it is quieter than the SR; however, I have not been able to determine whether it is necessary to modify the ECU with the INJEN. I know that the SRT comes with a ECU "modifier" while the INJEN does not.

Any advice on this would be greatly appreciated...

 

No worries with rain unless you custom fabricated an intake that went down through the the panel below it into the fog light area where it might suck water in, but an Injen, SRT, or the K&N I have are all fine.

With the Injen you may gain a bit of power in upper rpms but will probably lose a bit of low end torque without any modification to the air/fuel via an SAFC or other device.

I have the K&N intake with an SAFC-II I had tuned on a dyno to maximize the intake/exhaust combo I have. From memory I think I gained about 12 rwhp and rwtorque.

 

Dude, go SRT I gained 25WHP + 35WTQ
if u go injen get a bi-pass valve because it goes pretty low...my buddy just got on his 04 maxima