That box that sits on top of the I6 motors is the intake resonator. Many aftermarket intake kits bypass the resonator, some do not. No real power difference, I don't think, just more for sound.
I removed mine and DIY'ed a new pipe instead. The intake noise is quite a bit more noticeable especially at WOT. This is a mod more for fun then performance IMO.
How's the engine efficiency without it? given that more hot air will come in
This is an aggressive post. You probably won’t like it. It is quite doubtful that you have the taste or sophistication to be able to appreciate a post of this quality and depth.
My K&N intake kit bypassed that resonator. I'd say there are minimal gains in removing it, but I am going to modify it to go back on over top of the motor to keep crap off of the coils.
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