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Discussion Starter #1
This weekend I helped a buddy of mine install a Tsudo uppipe into his 04 WRX. The car is basically stock except for a ATR cat-back exhaust, TurboXS BOV, and of course a newly installed upipe which is giving us all kinds of problems. We have the expected CEL so I guess today we're gonna hafta reset the ECU and stick in a 2.2k ohm resister. Anyway, before we get out to the garage and tackle this thing again today there are two other issues at hand which I thought I'd get some opinions on before starting.

The first is performance, The car doesn't pull anywhere near as hard as it should, despite making what seems to be proper boost pressures (between 12-13 psi peak, and much more quickly now I might add). :eek: I'm guessing the ECU is just retarding the ignition timing or throttling back the engine somehow due to that blasted CEL. My buddy is really worried, but I think this problem will most likely disappear when the CEL is cleared and the ECU is happy again, am I right?

The second issue is sound. Now I realize that anytime you remove a catalytic converter that you're gonna a have slightly louder exhaust note coming out the tailpipe, but his whole engine seems to be much louder overall, as in there is more noise up front. I don't think he has an exhaust leak anywhere in the manifolds or uppipe because the turbo does spool up noticably quicker than before and still puts out 12-13 psi like it always did. The car wouldn't make boost in those pressures if there was a leak in the manifold or uppipe, correct? I do know there is one exhaust leak between the downpipe and the mid-pipe which we're gonna fix this morning, but I can't see how it could contribute that much overall to the volume levels, especially towards the front of the car. Additionally his BOV, which is normally crazy loud is acting rather quiet and subdued despite the fact that the turbo seems to be spooling and doing it's thing just fine. :confused1 Any ideas what could be up with that or will it likely be back to it's normal noisy self when the CEL is cleared?

Thanks in advance, and sorry about the long post.
 

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Up pipes don't add "that" much power, I installed mine one night and it felt basically the same,..but since I had a mbc I decided since I removed the pre-cat I could turn up the boost more and thats when it felt much better. I believe up pipes are only good for about 5-10hp so its not too noticeable on the butt-dyno.

Also if you had an up pipe leak you would DEFINITELY know it, its one of the loudest leaks I have ever heard (besides an intercooler leak) it makes a very loud shreeking sound when you get into boost.

I would definitely second the ECU "learning" the mods...after every mod (until I got utec) my car felt like a dog until a week or so. But iirc cel's from missing cats aka cat inneficiency do not cause any power loss whatsoever.
 

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SERacing said:
Up pipes don't add "that" much power, I installed mine one night and it felt basically the same,..but since I had a mbc I decided since I removed the pre-cat I could turn up the boost more and thats when it felt much better. I believe up pipes are only good for about 5-10hp so its not too noticeable on the butt-dyno.

Also if you had an up pipe leak you would DEFINITELY know it, its one of the loudest leaks I have ever heard (besides an intercooler leak) it makes a very loud shreeking sound when you get into boost.

I would definitely second the ECU "learning" the mods...after every mod (until I got utec) my car felt like a dog until a week or so. But iirc cel's from missing cats aka cat inneficiency do not cause any power loss whatsoever.
What SERACING said, the up-pipe doesnt add much power, i only feel the spool faster in high gears. And like SERacing said also is the leak is an annoying sound.
 

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Discussion Starter #4
Okay, my friend and I took a look at things again today, and it appears that we were just getting tired and sloppy towards the end of installation because the first thing we noticed was that the hose clamps were never tightened down on the hose that runs from the intercooler to the throttle body. :eek: That might explain why the turbo was making boost yet the car was performing so poorly. It also fixed his blowoff valve which is once again obnoxiously loud. We also reset the ECU and the CEL went away. Hopefully it won't return and he won't need to do the resistor mod. Also, fixing the exhaust leak between the mid-pipe and the down-pipe definately quieted the car down a great deal. That exhaust leak was rather misleading because the sound totally sounded like it was coming from further up the car. Lordy, I am sooooooo glad that is over with. I need a beer.
 
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