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-   -   Need help with Stillen HFC's (https://www.myg37.com/forums/intake-and-exhaust/187839-need-help-with-stillen-hfcs.html)

kaos2774 Nov 29, 2008 09:49 PM

Need help with Stillen HFC's
 
I had stillen's HFC's in stalled and about a month later my SES light came on had it looked at and it was determined that the gaskets were leaking. So I replaced the gaskets and it stopped the leaks but they started leaking again. Has any one had the same problem? and how did you fix it? Cobb AP said the problem is with cat 1 and 2 code Po420.

IvoryG Nov 29, 2008 10:02 PM

With anything exhaust related you should go check the the bolts at 500 miles after install. I have always done 500 and 1000 on all my cars. Expansion and contraction will cause the bolts to loosen up. After that you should have no problems.

BerkTechnology Nov 29, 2008 10:51 PM

You need a set of gaskets in there. The Stillen flange makes use of the OEM crush ring but the tolerances aren't quite close enough to allow the crush ring to seat properly.

Your options:

1. Smear a crap load of RTV sealant on there.
2. Get a set of our custom made gaskets on there.

But remember with either method (new OEM, spreading goop, or a gasket) it's essentially a R&R.

Similar to the one pictured, but for the 3 bolt collector flange obviously.
http://www.berktechnology.com/shop/u...oducts/467.jpg

Skyline-LEXY Nov 29, 2008 10:54 PM

are you sure its the leak? cause i have the same issue... I spoke with Kyle@stillen and he said they are working on something to fix this issue.

btw p0420 and p430 means too much air going in to the sensor... I dont think its the leak.

was the leak from the header and hfc or hfc and mid-pipe?

BerkTechnology Nov 29, 2008 11:48 PM

Another thing to note.

Stillen uses the same cat that we do. The cats don't scrub the exhaust gas quite as well as the restrictive and OEM cats do. So CEL free operatoin isn't absolutley guaranteed.

The the OP, try using the stainless steel wool trick. Pickup a set of non-foulers (just search for it if you don't know what it is) and stuff them with stainless steel wool.

kaos2774 Nov 30, 2008 04:18 AM


Originally Posted by Skyline-LEXY (Post 2476387)
are you sure its the leak? cause i have the same issue... I spoke with Kyle@stillen and he said they are working on something to fix this issue.

btw p0420 and p430 means too much air going in to the sensor... I dont think its the leak.

was the leak from the header and hfc or hfc and mid-pipe?

Sent a pm to Kyle@stillen I hope he can do something about this. I was hoping that the Cobb AP was going to fix this problem. But my SES light was on before I had my CAI and my HKS exhaust installed. Just with the HFC's

Skyline-LEXY Nov 30, 2008 04:23 AM

i spoke with Lou about Cobb AP and i think he said it wont fix that issue because AP doesnt control AF.. because of the liability

kaos2774 Nov 30, 2008 04:24 AM


Originally Posted by BerkTechnology (Post 2476418)
Another thing to note.

Stillen uses the same cat that we do. The cats don't scrub the exhaust gas quite as well as the restrictive and OEM cats do. So CEL free operatoin isn't absolutley guaranteed.

The the OP, try using the stainless steel wool trick. Pickup a set of non-foulers (just search for it if you don't know what it is) and stuff them with stainless steel wool.

I'll look in to it thank's. My car run's like sh-t with the SES light on

Skyline-LEXY Nov 30, 2008 04:25 AM

btw do you still have that raspy noise from HFC with your full exhaust system?

Skyline-LEXY Nov 30, 2008 04:31 AM


Originally Posted by BerkTechnology (Post 2476381)
You need a set of gaskets in there. The Stillen flange makes use of the OEM crush ring but the tolerances aren't quite close enough to allow the crush ring to seat properly.

Your options:

1. Smear a crap load of RTV sealant on there.
2. Get a set of our custom made gaskets on there.

But remember with either method (new OEM, spreading goop, or a gasket) it's essentially a R&R.

Similar to the one pictured, but for the 3 bolt collector flange obviously.
http://www.berktechnology.com/shop/u...oducts/467.jpg

I am not saying your wrong because I totally agree with you. I spoke to Kyle@Stillen and he said "from the factory the cars come with steel gaskets which are virtually indestructible." When I was installing mine from Technosquare they said new gaskets were needed. So I totally agree with you with gaskets.

kaos2774 Nov 30, 2008 04:36 AM


Originally Posted by Skyline-LEXY (Post 2476630)
btw do you still have that raspy noise from HFC with your full exhaust system?

Yes. If your talking about the back pressure air sound yes

bunluvsvw Nov 30, 2008 01:08 PM


Originally Posted by BerkTechnology (Post 2476418)
Another thing to note.

Stillen uses the same cat that we do. The cats don't scrub the exhaust gas quite as well as the restrictive and OEM cats do. So CEL free operatoin isn't absolutley guaranteed.

The the OP, try using the stainless steel wool trick. Pickup a set of non-foulers (just search for it if you don't know what it is) and stuff them with stainless steel wool.

Does those Cel fix on ebay work? the ones that extend your 02 sensors more outward screwing onto the bung?

BerkTechnology Nov 30, 2008 04:47 PM


Originally Posted by kaos2774 (Post 2476629)
I'll look in to it thank's. My car run's like sh-t with the SES light on

If it is truly a P0420, P0430 (cat converter efficiency below threshold), it will have zero effect on engine performance.

The secondary O2 sensors only monitor the cat converter efficiency, they have no other purpose. :)

kaos2774 Nov 30, 2008 05:58 PM


Originally Posted by BerkTechnology (Post 2476874)
If it is truly a P0420, P0430 (cat converter efficiency below threshold), it will have zero effect on engine performance.

The secondary O2 sensors only monitor the cat converter efficiency, they have no other purpose. :)

When I clear the SES light with my Cobb AP the car runs great but when it comes back on the car seems to louse some power off the line.

jungwoo0622 Nov 30, 2008 06:37 PM


Originally Posted by BerkTechnology (Post 2476874)
If it is truly a P0420, P0430 (cat converter efficiency below threshold), it will have zero effect on engine performance.

The secondary O2 sensors only monitor the cat converter efficiency, they have no other purpose. :)

i had P2A00,P2A03(a/f ratio issue) b/c of the leakage befor the HFC since
i didnt have a gasket in there.

checked your web and couldnt find three point gasket for flange to the engine side.

If you have it PM me please.


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