you just asked questions that i will never need to know. when a car has a computor problem you don't need to know what it is you simply plug a nice little red box into a plug and tell it to run a computor scan. so i don't really know much about car computors. on the other hand the answers to the questions you didn't know are
cold air intake sucks up water becasue it puts the air cone to far down the engine compartment to have the block stop water, it also has a very thin filter cone with no plastic layer for stopping water.
headers are not just exhaust manifolds, they are larger take up more room and increase exhaust flow and disipate heat better.
free flow exhaust is just a differant way to quiet your car, you might have heard it called 'tuned exhaust' but that is wrong it is in no way tuned and that is a differant thing altogether. free flow exhaust has a straight ported pipe going through a cylender of noise dampening material because of its design it makes a louder higher pitched sound. well thanks anyway, and if you like miatas good for you, but i don't.
Peace
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Friend

ww shit my head!
me: what did you do?
friend: i fell down the stairs
Me: and you hit your head?
friend:No, my wrist
snoogins
Vancouver - good weed, hockey, and the Blunt Brother
Canada, better than the us
-an ashamed american