to those who have a catless downpipe and a whistling sound, did you do anything to get rid of it, like add a cat? i cant stand the whistling

 

any1??

 

describe this whistling. when does it happen and do you know why. I have the CA 2.5 with no cat and the only sound i get from time to time is the metal clank on start out of first. other than that i would check the gaskets and also check to O2 bung make sure everything is tight.

 

it happens when the car is under load when driving. not when idling, letting the car wind down, or hitting the gas lightly

not only did i check the downpipe myself, i brought it to my mechanic and he even said there is no leaks.

 

Only time I ever heard exhaust whistling is on my friends car which had a pin hole in it. Under load it sounded like a messed up turbo. Put on some miles and check it again for an exhaust leak. It'll be easier to see when some soot forms around the hole, if you do in fact have a hole.

 

u kno thats not a bad description of the sound... ugh like lookin for a needle in a haystack

 

Lol. It was really funny driving around with it since it was a ford escort that sounded turbo. It is like looking for a needle in a stack of needles. It's a pain, but at least you know it happened after the down pipe so you don't have to look at the whole exhaust for it at least.

 

yea it def is the downpipe, at least its better than the 3 foot hole i had in my stock downpipes flex section. lol but ill put some more miles on it.. and check for the soot. i hope it is somethin this simple so i dont have to spend any money on a cat or somethin..

 

i have heard whistling sounds before after a downpipe install. not on a cobalt yet. But i have a question for you. does the downpipe have a flex pipe? If so did you look inside of it? On some cheaper downpipes (like the ebay one i put on my 1.8t beetle, and the one on my bros srt-4) they are not double layer flexpipes. Its hard to explain, but you know what the outside of the flex pipe looks like, with all the braded stainless steel strands, the inside should look like that also. A cheep one you will not see the braded stainless steel inside when looking into it and it will look more like a slinky. If its a cheap one they can some times make a whistling noise.

I hope this makes some kind of sense.

 

I got the pacesetter and catless bolt on downpipe and i hear that dang whistling noise too. I was at my muffler shop this morning asking himto fix it. He said that whistling noise is created by the flex pipe. I don't really believe it. There has to be some solution to this, besides putting the stock exhaust back on.

 

if it is infact the flex pipe, VERY POSSIBLE, just order a better flex pipe from like summit or something. even most parts stores can get flex pipes, just get the size you need (make sure it is double sided braid) and get it welded in inplace of the whistler.

 

im pretty sure its not double sided.. ima order a better flex pipe and install that instead

 

just a thought, the stock downpipe isnt the double braided flexpipe and it doesnt whistle.... hmm

 

yea, but the cat will quiet any noise down. it acts as a resonator per say. with no cat on a catless downpipe (duh) it could amplify any design flaws.......

makes me wounder how it sounds when you gut the stock cat, maby a homework ass. for me tonight............