whats up everyone, theres a ton of info on HFC's, but my question is to those who have Stillens TD catback. Im looking at either Crawford or maybe F.I. hfc's, leaning more towards Crawford though. When you guys added this brand of hfc, how did it change your exhaust note? deeper, louder, almost the same (from what ive seen/read, neither have rasping issues)? a ton of youtube clips, but not with the Stillen combo.

 

Stillen's exhaust is manufactured down the street at Magnflow...fyi! If you are running the y-back system you may experience some rasp, not terrible! My experience with HFC's is I would never suggest anything but Fast Intentions, I have 30K miles + on mine without issues! Replacing OEM cats and adding HFC's will give you no less than 10 WHP along with a louder/deeper tone! Factory cats have so much restriction I often wonder how anything ever got thru!
What ever you decide, good luck and enjoy the ride...Gary

 

Thanks Gary, will be going with F.I. then. Was just worried about it adding that horrid rasp and having to replace them out again, and I'm pretty sure no company would accept a return once its been installed. I had even thought of just putting in new OEM cats, thinking those would have less restriction then my current 100k+ gummed up ones. Thanks again!

 

So, I finally decided to go through with Fast Intention resonated HFC, just to find out I cant because I live in California.. Anybody know the easiest work around? I do have family out of state, I can have them help me with this, but do you know if just the purchase has to be out of state? can he put my shipping address/his billing info? So technically it wasn't purchased in California? Or do we have to ship it back and forth? Just want them ASAP so I can get them sooner.

 

No aftermarket cats are legal in California. Period. Save your OEM ones for smog checks.

 

You can call the FI folks and ask, I think they just have the disclaimer on the site as a warning. Tell them it's for a race car or something.

 

I did find a thread from a few years ago saying to buy them soon, before the law takes effect. So I dont think it's just a disclaimer. Plus, I did email them, and they said they couldnt do it if I lived in cali. It's all good, just going to find another way.
With that said, when I DO order them, whats up with the 02 bung sensor? do I need 1 for driver side, passenger? Some of what im reading is it's for forced induction or for tuning. Which do I choose? Thanks

 

Fast Intention HFCs are a "Bolt and Play" installation, you'll need nothing! If you live in SoCal as long as you're not throwing and CES warnings getting your registration is easy! Give me a PM and save your OEM cats as a safety factor, we never know when Liberal Sacramento will change the rules...fact!
Gary

 

When you say plug and play, I do NOT need to order an extra 02 bung? Ive found a few threads saying its only for tuning (which I am going to do), or with forced induction (which I'm not). When ordering the options are: None, Driver side, Passenger side, both. If it's plug and play, I should select "none", and whatever sensor they come with will work fine, right?

 

Yep, the extras are for things like adding an exhaust temp gauge, etc.

 

Not true, there are a number of company's that make aftermarket cats, Magnaflow being one of them!
Joe, did you not get the # to my tuner I sent you? He should be able to order the correct HFCs for you!
Gary

 

That's good to know, are they ACTUALLY a better flowing cat though? I know flowmaster got some really bad press years back when they introduced a "CARB legal high flow cat" but it was just as restrictive as an OEM one in order to get the CARB stamp...

 

I did, and I called for a quote on the Uprev, which was a very reasonable price. But will they be able to get me a HFC? Im looking at HOW im going to get the Fast Intentions resonated hfc, but from what Ive heard and read, cannot be shipped if you have a California address. Will I be able to just order it through that shop? Or can I still buy them, and all that "illegal for purchase in California" stuff is just a disclaimer, and the order should go through? Usually they just throw in "for off road use only" and let you buy it at your own risk of getting a potential ticket or fail smog.. sucks, cuz thats the last thing I need before a tune. And I REALLY want the tune, lol

 

Actually, Stillen manufactures all their own exhaust systems, Magnaflow just builds the mufflers for them to Stillen specs. All of the actual cutting, bending, and welding is done by Stillen at their facility in Costa Mesa.