Installed test pipes w/ Borla exhaust today and now experience noise from 1/2 to full throttle. Sounds like a soleniod venting. Also have the same noise when de-excellerating at higher RPM. Almost sounds like a pop-off valve from a turbo (but don't have the turbo). Anybody have a clue what this could be???

 

Are the test pipes resonated?

Could the sound be a resonating/vibrational/rattling noise?

 

Mine are not resonated and have a terrible rattling noise.

 

sounds like an exhaust leak to me

 

I'm running the Helix pipes with a JIC y-pipe and stock exhaust system and am experiencing the same type of 'hissing' noise. It's most notable when I lift my foot off the throttle (kind of like on a BOV).

I noticed it right after I had the test pipes installed but it wasn't that loud. However, once the y-pipe was installed, it sort of amplified the noise.

I've gone back to have it checked out and the techs assure me that it isn't leaking but what else could it be? It seems like it has to be some type of leak.

 

2nd the exhaust leak

 

nobody knows? i was thinking about getting helix test pipes.

 

I really doubt it's the Helix's because other have installed those without weird noises. IIRC, there are other posts about the JIC not sealing properly and the Borla comes in 900 pieces, which makes it hard to avoid leaks.

 

Yeah, but the noises were present before the y-pipe was installed so there's something strange going on. Also, I got my y-pipe at Superautobacs and the kids that work in the service dept. find it quite hard to believe that JIC would ever make a defective y-pipe; whatever that's supposed to mean. They literally laughed at me when I suggested that perhaps the flange couuld have been off from the (JIC) factory. They said if anything's defective, it's gotta be the stock exhaust system which I've gotta say is probably a boatload of crap...

 

its very hard to determine what your problem is

i had an exhaust leak with my injen and you only hear it when you step on the gas..not let off

since everyone that has test pipes seems to be agreeing on this sound its pretty fair to assume that not ALL of us have leaks..i think when anyone puts on test pipes the and you take your foot off the gas it kinda sounds like a planes engine...which is a good thing cause its a cool sound especially if thats the sound its SUPPOSED to make

even if that doesnt make sense to anyone its still fair to say that you will hear an exhaust leak when you push hard on the gas not let off

an exhaust leak sounds like a "hissing" sound....the sound you described sounds more like what its "supposed to be"

the best way to test for a leak without jacking the car up....is getting into a higher gear (say 5th) and bring it down to the lowest mph at that gear....then step on the gas hard....if you hear a distinct hissing noise then its prob a leak

 

Sounds like an exaust leak 2 me,I am running with helix test pipes plus dc headers no rasp.

 

Check out the Thread "Raspy, buzzing exhaust @2500-3000 rpm. You should have bought resonated test pipes.

 

the raspiness has nothing to do with a leak....2 different things

if you do have a leak you would have it with resonated pipes or not

 

I don't know if this is what you are talking about, but a problem my friend had on his WRX when he got a new uppipe and downpipe was that the new uppipe used a different grade of metal so it expanded and contracted at a different rate than all the other metal in the exhaust so it started to sound super crappy at high RPMs.

 

I have the INJEN SES(angled) w/ Helix test pipe set-up. Ever since i installed the Helix TP, i've had a super strong gasoine/petroleum smell. Is it normal for this to happen w/ test pipes? Don't think i have a leak since i hear of no hissing sound.

Thanks.

 

Thanks Dave079... Wow, the smell is really strong.

 

gas smell goes away after a while..but comes back sometimes when you start punching the car

 

Maybe they installed a twin turbo instead of test pipes.