HFC's or else... what?

[earle2]

OK, let's say you're one of those folks that swapped out your stock cats for HFC's. What would you do now and why?

You like the change in the exhaust note, you wanted improvements in power, but you're done with error codes and want something that #1 works first and #2 improves performance. So, bite the bullet and go back to stock or pull the trigger for another upgrade? Or wait for another option to come along?...

[b8dsbA4]

I have a 200 cell cat that is completely bored out so it's like I'm running no cats. People do it for more torque and as far as error code s go I am apr stage 2 so I don't throw a CEL

[Unleaded20T]

you can gain extra Horses (up to 30 on a 2.0T) and with a good chip you no CEL. You need to request that the chip turns off the front sensor and leave the rear sensor on, in NJ it is only required one sensor reading for inspection purposes.

It's a cheap upgrade that gives you a LOT benefits.

[StratJohn]

Non-3.0T-Gentlemen, on the B8 S4, it is not as simple.

In this case several members of the board are already running a product which has been shown to ... not work. However, the install of said product required a ~6hr install.

So the question asked is, do you:

1) remove the HFC's and go back to stock (a 6hr install again, dropping the motor, and will require ANOTHER 6hr install should a new solution come about...

2) leave them on, and have lower power than stock, hoping that someone will have a better solution soon...

3) remove them and get wild, like a full catless header set up.. which will still throw a code, but give you some power back!
3a) Do that anyways and run some Strat 90* sensor spacers to kill the CEL... and just deal with having to pass visual inspection.

Because in a sense, that's pretty much it for right now.

[t0mt0m]

The B8 S4 is a sensitive beast and is very emotional. Mods on the same engine and platform does not always work with our cars...sadly

i believe i was one of the first few members on this board to try these hfcs. It gave me a new exhaust note and i was happy with that but with the cost of install becoming much more expensive than the price of the product itself; i noticed the bargain became more of a burden. I agree with circuit tested review but i am not tracking my car...that often since this is my daily driver. I am "living" with my decision of going 034 hfcs and installed stratjohns spacers that have mini cats in t. The cel went away and my baby is happy. I am tired of throwing codes and since test pipes throw codes and eurocode headers throw codes i am not switching over until apr offical announces they have killed the cel with there software which has not happened yet.

[apexit1]

Has anyone here ran the test pipes? It would seem that it would be the better option now that APR has the file for it. Question is does 034 even make them any more and what about the SAI codes that popped up. Has anyone been able to solve that?

[Fonzie@DipYourCar]

Has anyone here ran the test pipes? It would seem that it would be the better option now that APR has the file for it. Question is does 034 even make them any more and what about the SAI codes that popped up. Has anyone been able to solve that?

i've been running test pipes since March

[ENV²]

Fonzie runs the test pipes. Im thinking of doing a custom exhaust with 2.5" piping.... Ill make a thread later...

[richib86]

I am tired of throwing codes and since test pipes throw codes and eurocode headers throw codes i am not switching over until apr offical announces they have killed the cel with there software which has not happened yet.

they have an updated tune that gets rid of that CEL for you. now you have no excuse lol

[jc9963]

They officially have. My at has the NFC and was throwing the efficiency below threshold code. While they had my car, they developed the hfc/test pipe software.

[apexit1]

Has anyone found out what the SAI does though? Fonzie, have you ran into any issues?

[Fonzie@DipYourCar]

Has anyone found out what the SAI does though? Fonzie, have you ran into any issues?

My SAI codes come on every week. I clear them every time, but they come back up. I think Circuit Tested saw the same SAI codes - switching valves on bank 1 and bank 2 stuck open

The SAI is there to heat up the cats. I guess when it can't bring the cats to "temperature", (because the cats aren't there).. the vavles stay open and never close.

[richib86]

My SAI codes come on every week. I clear them every time, but they come back up. I think Circuit Tested saw the same SAI codes - switching valves on bank 1 and bank 2 stuck open

The SAI is there to heat up the cats. I guess when it can't bring the cats to "temperature", (because the cats aren't there).. the vavles stay open and never close.

I still don't get it. Other than that one time, I've never gotten this code again in all the miles I've put on. Circuit got the SAI codes with the LFC's not the headers

[Fonzie@DipYourCar]

Circuit got the SAI codes with the LFC's not the headers

yeah dude the only two people that saw the SAI codes have 034 products not headers

btw where the heck are the CircuitTested reviews on those long tubes?

[richib86]

yeah dude the only two people that saw the SAI codes have 034 products not headers

btw where the heck are the CircuitTested reviews on those long tubes?

I did get them once but it was a fluke reading. But then again who knows, I've never mounted the rear sensors so my car can't even get far enough into the readiness test to throw a SAI code lol I just know I've never felt a loss of power other than the isolated SAI CEL incident

[Info@EuroCode]

We have installed our headers in conjunction with our downpipes with HFC's result was no MIL. Circuit Test installed our headers with the 42 draft O2 spacers and no MIL recorded to date.

[Voltrons_Head]

OK, let's say you're one of those folks that swapped out your stock cats for HFC's. What would you do now and why?

Pay $1500 to a shop to have it put back to stock, trade it in for something else, and sell all of your mods in the az classifieds?

Just a thought.

[apexit1]

Lol. Might be an extreme reaction. Guess I'll keep Saving my pennies for the lth.

[NWS4Guy]

Pay $1500 to a shop to have it put back to stock, trade it in for something else, and sell all of your mods in the az classifieds? Then go buy a CTS-V and spend much less for more power.

Just a thought.

There ya go man, I fixed that for you

[earle2]

I've now seen 034 and even APR responding in another thread here that testpipes with APR's tune will make more power and will eliminate the CEL. I don't see the testpipes for sale from 034 and don't think anyone else is making them yet. Does anyone know if the swap from HFC's to testpipes can be done without dropping the engine?

[81bear]

I've now seen 034 and even APR responding in another thread here that testpipes with APR's tune will make more power and will eliminate the CEL. I don't see the testpipes for sale from 034 and don't think anyone else is making them yet. Does anyone know if the swap from HFC's to testpipes can be done without dropping the engine?

You shouldn't need to drop the enginee. The only reason you had to for the HFC's was because of the massive circumference of the stock CAT's.