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This past tuesday I had gotten a HKS downpipe, Blitz SUS LM, Perrin catch-can, and the intake silencer removed. These are my only mods. The tuning shop said I wouldn't get a CEL and that I wouldn't need to reset my ECU as it would re-learn and accomodate for the mods. Now I'm getting fuel cut at WOT right at 5500 rpms in 5 and 6th gear. After that, the CEL and Cruise light stay on, and I can't use cruise control. I live in CT so the air is cold. About 30 degrees cold. I know that doesn't help, but I didn't expect to get fuel cut without going full turbo back like everyone has been saying.
I'm going to the shop again Friday, so I'll see what they are willing to do. I know I probably have a few options: port the wastegate, get a mbc or preferably an ebc, remove the downpipe, or get a fuel cut defender (which could be more dangerous, I don't know). I'm wondering if there is anyway that I could keep the setup the same and fix the problem. Any input would be appreciated.

Btw, the mods have definetly added more topend and the cars feels more responsive and more alive. I did reset the ECU by discharging the battery etc. and the problem came back at the same RPMS I mentioned. I don't think pulling the CEL code will do much, because it will probably just be air/fuel related.
Is it harmful in anyway to hit the fuel cut? I imagine no, as it is more of a preventive measure, but I just want to be sure as I have already hit it about 6 or 7 times. :evil:
 

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The bost controller may help. I prefer EBC myself. Sounds like someone coped my stage 1 package but with an HKS downpipe. :wink:
ECU reset doesn't help. IN fact do not do it. ECU has to learn and that takes time and driving. If the problem continues with the EBC it is time to port the turbo. Yours is the first car I have seen hit boost cut with just downpipe and intake though. That's a first. Possibly it is due to the HKS downpipe though. THe opening is very small and I'm sure it does not flow enough ar for the wastegate. I have had no boost creep problems with my Godspeed or TUrbo XS units.
 

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Ya ebcs hit you right on the mark everytime, although expensive, they are very well worth the money. Good point about the downpipe, I didnt even think the opening had anything to do with it - As I figured it had to do with just getting it out of the turbo -, but that makes a lot of sense.

Robert~
 

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I have the same problem,without the intake.I got the P0244 code from only a Bosal downpipe,stock cat pipe and a Prodrive rear section.MBC here i come.lol

Rudy
 

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Rudy, the boost controller may or may not help. I usually tell people to get rid of both cats and keep stock exhaust. You'll have more power and usually, no boost cut problem.
 

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Rattling sound cure!

Guru said:
Rudy, the boost controller may or may not help. I usually tell people to get rid of both cats and keep stock exhaust. You'll have more power and usually, no boost cut problem.
hmmm ... I really hope I dont have any problems whenever I can save up enough $$$ for the GS downpipe. Also.. would running a higher gain setting on the SBCID III be better at stopping the boost cut problem (As it releases more gas - i assume more gain = more open the wastegate is)? I had it at 15 ... but wanted to turn it down to 14-13 as it was getting really cold at night and i started hitting higher boost... so I was just curious. Thanks again guru for all your help.

Robert~
 

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Thanks Dan,,you think if i put the stock muffler back on,would help any? as in,Bosal downpipe,stock cat pipe,stock tail section?

Thanks again

Rudy
 

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Re: catalytic converter and other cool things

jagcars26 said:
Thanks Dan,,you think if i put the stock muffler back on,would help any? as in,Bosal downpipe,stock cat pipe,stock tail section?

Thanks again

Rudy
also just to make it clear.. both cats are in the downpipe, meaning you're still catless. The catback (mid pipe and axel end) ... have just a resonator and a muffler in them. So you will still be catless.

Robert~
 

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I believe the Bosal downpipe only replaces one cat,,I could be wrong though,,hmmm gonna go look tomorrow.

Thanks all

Rudy
 

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really? how does that fit up? hmm... sorry about that, I figured it'd delete both like most downpipes..

goodluck

Robert~
 

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Guru said:
The bost controller may help. I prefer EBC myself. Sounds like someone coped my stage 1 package but with an HKS downpipe. :wink:
ECU reset doesn't help. IN fact do not do it. ECU has to learn and that takes time and driving. If the problem continues with the EBC it is time to port the turbo. Yours is the first car I have seen hit boost cut with just downpipe and intake though. That's a first. Possibly it is due to the HKS downpipe though. THe opening is very small and I'm sure it does not flow enough ar for the wastegate. I have had no boost creep problems with my Godspeed or TUrbo XS units.

Hey Dan,

Is the HKS DP opening smaller than the Stock STi DP opening?

I'm trying to get an understanding of how DP's cause boost creep? I know what the definition of boost creep is but not how DP's would cause this?

Can you explain this?

Thanks,

Brian
 

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i have an hks down pipe and stock exhaust....i have no boost creep....no power loss...but i still have cel and blinking cruise....and i've been told by the shop that i'm hearing the wastegate wapping(it sounds nasty...bad nasty not good)....i have gt spec II headers as well....what is the deal....i'm puttin 272hp to the wheels...so no prob there...but it's just buggin me....anyone,anyone
 

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bcristea said:
Guru said:
The bost controller may help. I prefer EBC myself. Sounds like someone coped my stage 1 package but with an HKS downpipe. :wink:
ECU reset doesn't help. IN fact do not do it. ECU has to learn and that takes time and driving. If the problem continues with the EBC it is time to port the turbo. Yours is the first car I have seen hit boost cut with just downpipe and intake though. That's a first. Possibly it is due to the HKS downpipe though. THe opening is very small and I'm sure it does not flow enough ar for the wastegate. I have had no boost creep problems with my Godspeed or TUrbo XS units.

Hey Dan,

Is the HKS DP opening smaller than the Stock STi DP opening?

I'm trying to get an understanding of how DP's cause boost creep? I know what the definition of boost creep is but not how DP's would cause this?

Can you explain this?

Thanks,

Brian
Sure. Okay you have two openings on the turbo outlet and then load and flow to factor in too. Now then. With stock downpipe you have small opening but also two cats to restrict flow from turbo outlet, thus no boost creep. Now then, take my downpipe, wider opening, no cats, very high flow but there is plenty of room and no turblulence so wastegate gasses are evacuated properly and thus no boost creep. Enter HKS downpipe, also cat free but with small opening. Turbo outlet gases no problem lot's of flow and lot's of turbulence and little room for wastegate gases to evacuate. Add high load situation like high speed you get voila, boost creep.
 

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Brian you should stop by the new place if you're ever around Novi. We're having a dyno day tomorrow. We now have full custom fabrication facilities complete with MIG and TIG welders and tube bender (for roll cages).
 

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Well while I get my new godspeed downpipe put on monday, Im just goin to have my mechanic port out my wastegate some :D hehe didnt even think to do that, but I will post results. Im sure it'll be good and I dont expect boost creep with the stock catback and GS DP, but Im sure it'll prevent any problems in the future. That and I'll let you know how easy it is/or how difficult.

Robert~
 

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Keep us posted on the boost creep thing,,Im doing what Dan said also,I just got a 3rd cat eliminator to go with my Bosal downpipe,going to put the stock cat back on and go from there.
Im just wondering if those of us that have really hot summers and cold winters could do like a summer/winter exhaust setup to control the boost creep.Free flow full turbo back fr summer,a little more restricted come cold weather.Any thoughts??Dan? etc,,,

Rudy
 

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I usually tell people to get rid of both cats and keep stock exhaust. You'll have more power and usually, no boost cut problem.(quote from guru)

I assume you mean downpipe with stock exhaust from there, sounds great but I cannot do this here in california. probably wont install anything until i can address engine management. but, i probably could gut my cats. surely safe to do, probably substantial gain (hp and spool up), but am i going to get a cel? i would imagine so, but some downpipes seem to be catless and not giving cels.

what do you guys think? i would rather be safe than sorry so i am looking for "catless cel cheat" to have ready before i do this. i saw a cheat for sale in one of threads from a company, but in a week i havent been able to find it again. please help.
 

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My catless downpipe has a built in fix so no CEL problem. No wiring involved either.
 

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It's been beat to death, but I need speaker help

Guru said:
My catless downpipe has a built in fix so no CEL problem. No wiring involved either.
and it is beautiful! but the california highway patrol will not think so, thanks guru for your quick reply, i would buy one of your downpipes in a heartbeat if my car was track-only, but it is a daily driver. smog equipment is a very serious issue here in california, and i cannot risk a several thousand dollar ticket or worse because i did an illegal mod on such a high profile car.

i was really hoping someone would answer my question(s)

opinions on gains from gutting cats on stock exhaust? worth it?
going to throw cel? (wouldnt it if cats are bad or nonexistant?)
cel fix thats tested? would raising the sensor out, (like on godspeed's downpipe i believe) fix the cel?
 
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