Unichip will not do anything for a component it doesn't connect to. It changes the values that the ECU sees, it doesn't modify the programming of the ECU in any way. Unichip doesn't connect to the O2 sensor, there's no way to fix that issue with it.

Additionally, for Unichip to perform at its best (not accounting for stars aligning) you need a map designed for the mods you have. I haven't looked for myself, yet, since I already have the maps I want, but you should do some research to see if the mods you're doing fit well with that solution (unless you are or plan to hire a Unichip tuner).

I think you need to do a lot more research with your choices on aftermarket parts. Check out the FI thread. There's plenty of people running headers that are just fine size wise and producing great numbers with the vortech kit and the innovate kit. Pick one you like, research it, and buy it if you want. You aren't going to find many large headers because this is only a 2.0L engine. Exhaust on the other hand, you'll find up to 3".

I would say to go with Borla at least for now. Here's why:

•They're pretty cheap.
•They're the lightest headers available right now.
•You can sell them later when you go FI if someone releases some really good S/C-supporting headers.

Lots of people talk shit about the Borla headers, but most of it is just that a few people had problems (there was indeed an early batch that was bad) so everyone else thinks all Borla headers are garbage and spread that attitude around the forums like fire. You'll also find lots of comparisons between the quality of welds on the Borlas vs pretty much every other set. Yes, the Borlas have probably the worst looking welds on the market, but I have yet to hear of someone having cracked welds.

I'm hoping in the future someone will release some obtainable high quality titanium headers. Until then, I went with a used set of Borla headers. Three hunnah bucks. When/if the time ever comes to upgrade, I can probably sell them for what I paid for them or at least really close to it. If you want headers NOW but are concerned with diameter for a future FI build, my recommendation is to do the same thing I am: cheapos for now, upgrade later.

But as it's already been mentioned, I think you'll be fine with just about any set in regards to their diameter restricting air flow behind a supercharger.

If weight is a concern for you, and it should be if you care at all about performance, here are some numbers to make your decision even more complicated: http://www.ft86club.com/forums/showthread.php?t=42555
You're welcome.

Ok, i have a question i am about to buy a header (inclined in the borla) but i dont want to go cat less) is there any header out there, were i can keep the cat? And i can just put a high flow one?? Or should i just not get the header and buy the high flow cat instead?? My set up is a Greddy evo 3 exhaust and blitz cold air intake

You'll have to get headers that have high flow cats in them. I've always wanted to go catless though, so I don't know what your options are. You can also get front pipes with high flow cats. If you're trying to comply with emissions requirements, then I don't know how many you'll need to keep within regulations.

The only catted UEL option I know of is FA20club's. It's more geared for in preparation for turbo later the way it wraps around in front.

Thanks, so should i go for that header? Ir just get the high flow cat?

Why do you want to keep the Cat? FL has no inspection. (Boricua here too).

Get a tune with the header. It's well worth it.

You'll still keep the frontpipe Cat.

2 reasons: 1) im military always on the move
2) i dont want to have to deal with the check eng light

A tune should cure up the CEL and any intake/exhaust upgrades without a tune is just silly anyway.

Aight, so what header should i get then? (Im thinking borla uel)
And does anybody kno a good tune place on clearwater area?

Well, I can understand if you are on the move wanting to keep the Cat.

About the tune, get a remote tune for it. FA20club here in south FL can take care of you.

Borla or FA20 header as mentioned, my preference and what I'll go for is the fa20 simply cause it caters to both NA & FI applications by its design. Don't forget companies like Avo Turboworld make 5" high flow catted front pipes so you can go with an un catted header with that option in mind as well as their front pipe also has a bung for your O2 sensor on the front pipe.

And as sports guy mentions you're in the right state, fa20 is right there, give em a call they have everything you need to get pimped out. Hell if I lived where you are, it's honestly a NO BRAINER. :)

I'd go catless. First off, catted is more expensive on the header. Two, more likely to fail quicker than a front pipe cat due to the high flow through the header.

Like he said, keep the cat in the front pipe and call it a day. Unless emissions requires you to have two, I see no real reason, but if you're already looking at an aftermarket header, emissions is out of the question, catted or not. 99% of them all say "off-road use only"