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2014 Forester XT Touring CVT
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Discussion Starter #1
aight so this past weekend i just installed a Cobb catted DP to mate with my already installed Cobb CBE and a STi TMIC.. now everytime i go 1/2 throttle n up.. it sounds like i have an exhaust leak.. that loud ticking plus im gettin pretty bad gas mileage than before.. i put new OEM gaskets in both turbo-dp and dp-cbe (donut gasket)..
is it true gaskets take time to expand to create the seal? or is my ish not snug enough? its been 4 days since install.. n just gettin a little worried..

thanks
 

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2004 Subaru FXT MT
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Well, with time, I suppose you could clog the leak with carbon buildup. But not highly likely.

You probably have an exhaust leak and need to go around and recheck your torques. Sometimes these things can be a bear to whip. Just the way it is.

I installed a grimmspeed crossover and manifolds that I P&P'd myself on Monday, and I have an exhaust leak too with proper torque on everything. Still have an exhaust leak that I can't find. All new gaskets too....
 

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You might just be hearing your turbo more with the aftermarket DP. Same thing happened to me where I thought I had an exhaust leak. I would only hear it when the turbo began to spool up. My first downpipe (Helix) I didn't hear any noises like that, but when I put my Maddad DP on I did. I had my friend listen to it, and he said his car sounded the same with the Cobb catted DP on. I eventually had the car checked for leaks with a smoke machine, and no leaks.
 

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Discussion Starter #4
You might just be hearing your turbo more with the aftermarket DP. Same thing happened to me where I thought I had an exhaust leak. I would only hear it when the turbo began to spool up. My first downpipe (Helix) I didn't hear any noises like that, but when I put my Maddad DP on I did. I had my friend listen to it, and he said his car sounded the same with the Cobb catted DP on. I eventually had the car checked for leaks with a smoke machine, and no leaks.
hmm really? cause my exhaust leak sound is pretty loud.. the ticking resonates pretty loudly when in between cars or next to a wall.. but it sorta does go in conjuction with the turbo spool.. like it ticks in beat with the turbo whistle
 

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hmm really? cause my exhaust leak sound is pretty loud.. the ticking resonates pretty loudly when in between cars or next to a wall.. but it sorta does go in conjuction with the turbo spool.. like it ticks in beat with the turbo whistle
You have a boost gauge? I don't ever hear it at idle or very light cruising...It starts when the gauge reads around -10 Hg, and I hear it go away as I left my foot of the gas lightly.

I'd recheck the torque on the bolts for the turbo to DP though, they might loosen up after a few heat cycles.
 

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Discussion Starter #6
You have a boost gauge? I don't ever hear it at idle or very light cruising...It starts when the gauge reads around -10 Hg, and I hear it go away as I left my foot of the gas lightly.

I'd recheck the torque on the bolts for the turbo to DP though, they might loosen up after a few heat cycles.
oh i dont hear it during idle either.. only when gassin it n it goes away when i lift off the gas also.. i was referring to u saying the DP makin the turbo sound louder.. i def know the turbo sound.. n it def sounds like an exhaust leak.. like a diesel truck.. but yea im gonna check everything again this weekend thanks all
 

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Yes, gaskets will take a heat cycle to seal. But as I recall you don't see much past the first heat cycle. We did an evaluation a while back.

But your conclusions somewhat don't add up. The parts you changed are after the turbo and thus really shouldn't have much affect on gas milage. Unless you have such a gross leak that it's throwing off the O2 sensor, but I doubt that. I'm guessing your gas milage is a factor of flooring it constantly to feel the new mod's and also listen for the leak.

Getting the DP to torque and not leak can be a PITA and I've also noticed that a lot of DP's hang a little off and cause the mating to the mid pipe to be all goofy.
 

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Discussion Starter #8
Yes, gaskets will take a heat cycle to seal. But as I recall you don't see much past the first heat cycle. We did an evaluation a while back.

But your conclusions somewhat don't add up. The parts you changed are after the turbo and thus really shouldn't have much affect on gas milage. Unless you have such a gross leak that it's throwing off the O2 sensor, but I doubt that. I'm guessing your gas milage is a factor of flooring it constantly to feel the new mod's and also listen for the leak.

Getting the DP to torque and not leak can be a PITA and I've also noticed that a lot of DP's hang a little off and cause the mating to the mid pipe to be all goofy.
actually as of yesterday.. my gas mileage went back to its usual 320 miles per full tank.. 80% highway 20% city so im guessin maybe the ECU just needed to relearn.. and this is with gunning it at times.. but i still hear the leak.. im thinkin its the turbo-dp area cause its tick matches turbo spool.. sorta makin it sound like wastegate flutter but its not.. i know what that sounds like n when it happens..

but fitment issues were no problem (guess thats why Cobb is so expensive for its quality) n the mate between the cobb dp n cobb cbe were perfect.. i mean it did have a bit of space in between but it seemed normal since thats how the stock pieces were
 

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Discussion Starter #9 (Edited)
ok.. so i think im missing a gasket.. part # 44011FE000 (for pic click here).. would this be why i have an exhaust leak?

and does this gasket work in conjuction with the graphite donut gasket??

**EDIT - nevermind.. its sayin this goes inbetween top part of DP n bottom part of DP.. my DPs one piece...
 
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