I just bought the car and I have seen it is suppose to add 20hp+ and so forth but I think is BS. So I am asking here in the forums where it should come close to the truth. This is what I have under the hood exactly for my GS300 '99. It's the SRT Intake with ECU.

How much hp does it really add. Cuz the lil roar is not a fav of mine and maybe I'll sell it and put the oem intake back on.

 

My friend used to have the SRT intake on his IS300. Same motor as our gs300's. I believe the SRT does yield an increase in power output of up to 15-20hp as claimed. However where it does that increase is mostly in the higher rpm's. Also, if im not mistaken the SRT intake will reduce your low end torque but makes up for it in top end power. It is also one of the loudest intakes for our cars.

Also, i'm looking at that picture of your engine bay. It seems like the previous owner did quite a bid of modding. The exhaust headers dont look stock to me as well as the half missing strut bar pieces still on there.

Hey, if you dont like the intake. I got first dibs on it if you plan to sell.

Edit: Ah, nevermind I noticed you have a 99...MAF not compatible with mine. I'm sure plenty of other guys here will buy it from you tho.

 

Those headers are stock, I noticed different year gs-3's have different exhaust manifolds.