dj_unforgetable

Is it true that if I wanted to install a new header on the car I would need to get a new midpipe since the stock header has a cat on it? I went to a local store and they said for headers I would need to do an SI conversion...essentialy get the SI header, a new midpipe and another peice which I'm forgetting. It seems reasonable but I wanted to confirm here...

durell_banks

They would install an Si header, install/move your cat to underneath the car, move the o2 sensor, and then put on a new exhaust if that's what you want. I assume you also want a new resonator. OR, you could install the header, move the cat to under the car and leave it like that, I think.

chris_si98

you can get a header made for your exhaust setup.. but it would be absouletly pointless. it wont yield any power.

IMO.. even if you switch to an si setup.. you still wont make any noticeable horsepower. And you'll most likely lose a-bit of low-end like I felt when i upgraded my exhaust sys. on my d16.

You dont need to modify your midpipe, but its a good idea. Any exhaust shop could but a reducer in for you if you really wanted.

durell_banks

chris is absolutely right - you will probably lose a bit of low-end power. I have an '03 sedan with I/H/E, with a 4-1 header and a cat-back exhaust. You gain a bit of higher-end power, but that's mostly noticeable at max. speed. Otherwise, no real noticeable power difference, just a louder car.

dj_unforgetable

So I'm pretty much stuck at stock in terms of performance upgrades....I dont wanna do an engine swap so i guess all I can do is exterior....

I wanted to actually increase low-mid range power since thats usually where my rpms are for dd, obviously higher for highway but thats more rare...