weird hiss after installing 2.5 downpipe
09-20-2011, 09:52 PM
#1
weird hiss after installing 2.5 downpipe
so i just installed my zzp 2.5 catted downpipe on thursday. and now whenever i drive and my rpms get above 2500 i hear a loud hiss. i went to the shop who did my install and they lifted the car revved it and saw no leaks what soever the gaskets are on and fine and all that. i didnt get any code the 1st start up after install. and havent gotten anything to this day.. but the tech said that it was my intake. i have the 2.4 K&N SRI. it didnt do this before the downpipe but it does now. i have the gmpp exhaust also.
so did the downpipe make the intake suck in more air than before the downpipe? my filter is about 2 years old so i just bought a new one. just unsure why it does this. it doesnt sound good either at WOT and all that it sounds like ****. but the tech did rev my engine and i was infront of it and it did sound like the filter but im still left with no answers. so if anyone knows why im having this problem please help me out
so did the downpipe make the intake suck in more air than before the downpipe? my filter is about 2 years old so i just bought a new one. just unsure why it does this. it doesnt sound good either at WOT and all that it sounds like ****. but the tech did rev my engine and i was infront of it and it did sound like the filter but im still left with no answers. so if anyone knows why im having this problem please help me out
09-20-2011, 09:58 PM
#3
well it sounds like it comes from the filter. but when i rev in park and get to 4k it sounds liek its going thru the whole exhaust and out the tip. i wish i can get this sound on record. i will have to try.but i want to get rid of it because when driving and getting on it a little it really sounds like **** like something is wrong.
09-20-2011, 10:01 PM
#6
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Yea i know what you meen, mine only does it when i drive, it could aslo be from the the type of muffler i use, but when i rev it a little i dont get the exact same sound, i think someone else on here posted a thread of a similar problem
09-20-2011, 10:02 PM
#8
When you change exhaust parts your going to get different sounds. When I went to the stock DP with the SS exhaust on my LS, the sound got a little deeper all around. When I swapped to the catless DP with the SS exhaust, the sound got even deeper, but it has a little bit of rasp now.
In order to get the sound you want your going to have to experiment with different setups and decide which one you like best.
In order to get the sound you want your going to have to experiment with different setups and decide which one you like best.
09-20-2011, 10:04 PM
#9
and i reallly dont remember it doing this on thursday or else i would have gone back
and it isnt the exhaust note because it does sound different. it just sounds like its coming from my intake sucking in a lot more air than before
and it isnt the exhaust note because it does sound different. it just sounds like its coming from my intake sucking in a lot more air than before
Last edited by Cobalt08LS; 09-20-2011 at 10:04 PM. Reason: Automerged Doublepost
09-20-2011, 10:06 PM
#11
gmpp. the noise i hear starts the second i get on it. even as about 2300 i can slowly start to hear it and it gets louder the more i put the pedal down
its not the bubbling from the exhaust im talking about its different. its hard to explain.
its not the bubbling from the exhaust im talking about its different. its hard to explain.
Last edited by Cobalt08LS; 09-20-2011 at 10:06 PM. Reason: Automerged Doublepost
09-20-2011, 10:10 PM
#13
yea thats what im thinking. because when the tech revved it when i was standing right in front of the cone i heard the exact noise it was making. so igot a new filter im going to install it when i get it and see if it fixes my problem
09-20-2011, 10:11 PM
#14
you just upgraded from the stock dp to the ZZP 2.5 catted.... it very well could be that your hearing the intake pulling more air in.
*Sidenote - I just helped my buddy with an RSX install his intake, and now when he revs, you can definitaly hear it pulling more air.
DAMN LS2SS just posted the same thing i was typing
*Sidenote - I just helped my buddy with an RSX install his intake, and now when he revs, you can definitaly hear it pulling more air.
DAMN LS2SS just posted the same thing i was typing
09-20-2011, 10:12 PM
#15
yea. well its not the sound of the intake that it did when ifirst got it. its a totaly different noise. it just sounds wrong. like its sucking in too much air or something. i have the 2.4 intake and im a 2.2 does that matter. i just dont like the noise it makes because it sounds like complete ****. i use to like messing around with my car i mean if i have radio or something on i wont hear it but if someone hears me fly past they probally would say whats wrong with your car
09-20-2011, 10:15 PM
#17
the 2.4 intake shouldn't make difference on the 2.2 inless the outside diameter is different on the throttle body then the inside diameter on the coupler that mates the 2 together
on that note i think the AEM, Fujita, and Injen CAI's for the 2.2 and 2.4 are all interchangable.
on that note i think the AEM, Fujita, and Injen CAI's for the 2.2 and 2.4 are all interchangable.
09-20-2011, 10:29 PM
#22
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I'm having the same problem with my car. I went catless and I get a hiss. I came to the conclusion that it was just the sound of the air flow through the exhaust not the intake. But I know what you mean abt it being annoying as hell. Lol. I can't stand it.
09-20-2011, 10:30 PM
#24
Senior Member
if it is rasp.... I've *heard* throwing on a glasspack+running a muffler will help that. can somebody confirm this?
Mine rasps around 3-4k w/magnaflow catback, and stock decatted dp
Mine rasps around 3-4k w/magnaflow catback, and stock decatted dp
09-20-2011, 10:32 PM
#25
it just sounds like my car sounds like **** and isnt proper.
its not rasp im talking about. i have a video of me revving it after igot it installed and it sounds fine
Last edited by Cobalt08LS; 09-20-2011 at 10:32 PM. Reason: Automerged Doublepost