Hi, I recently purchased a High flow cat/downpipe from zz performance. I got it very quickly and had it installed this morning. There is a very noticeable noise that comes from it. It’s a sound that’s very hard to describe but can be heard even when your radio is on full blast. It doesn’t happen when you idle or slowly acelorate, only when you give it some gas pretty hard. It kinda sounds like a rattle but like more then 1 rattle at a time. I talked to the mechanic who installed it for me and he said that may be normal at first and to give it a few days to settle in. I was currious what you guys thought about that? Best way I can describe it is if you put 150 pieces of rice in a metal sealed pot and shook it. I have only driven it hope from the exaust shop, so if this is it just wearing in, how long should I have to wait to see it reduce or go away?

 

after any exhaust work dont go WOT! after 100 miles of installing a header, down pipe, cat back etc. you should baby the car till 100 miles then have all the bolts re tightened. if u like do it again after another 100 miles. this will make sure that your exhaust stays tights with minimal vibration and zero exhaust leaks. gratz on ur purchase

 

plus its not coated in carbon yet to dampen the sound.... my whole system does it still lol cuz i went header back at once its dieing down though

 

Got it, guess I will give it a while and see how things go. Thanks all.

 

OK now that its not raining and we put the windows down we believe it to be an exaust leak now. My brother says he can see the gasket hanging down. Unfortuately I dont have time to fix it until tuesday so I will update once we fix the gasket and retighten everything up.

 

the noise sucks it better go away!

 

So I take it you get the noise too? LOL.

So far it does appear to get better, but it hasnt gone away for me yet.

 

As far as adding power how do you think the downpipe and high flow cat did?

 

Did You Guys Re Tighten?

 

I did, according to my butt and my interceptor no power gain....

Does sound louder though which I like minus the annoying noise

 

how far are you torqing it down?

 

i emailed zoomer he said the noise will go away with a 1500 miles or a month which ever you do first. the sound is no carbon build up in the cat so it is vibrating!

I feel alot faster up top 5-7k but down low it feels the same me and xenozx will have a video of are cars once the 2.8" pulleys come in!!!!!!!!!!!!!!

 

I got mine w/ no cat. Plan on installing it tonight. Will keep you guys updated.

 

I hope thats right

 

Till it wouldnt move any more LOL. We did it with just a regular wrench, but that thing wasnt moving any further, and we used washer locks.

 

good idea with the washer locks

 

I just got done installing my J/S header and zz perf DP w/out CAT. Anyone else have a high pitch wistle like sound when accelerating? The gaskets were all in good shape and everything was tightened down... so i dont think anything is leaking. Maybe its the DP breakin in or something.

 

Do you read? yes... I made this post and another that talk about it. Drive for a while and it will start to go away. ZZP says it should go away after 1500 miles of driving. Its cause you need carbon to build up inside the tube, as its sound dampening material.

 

Thats good news!

 

Yeah really, stupid annoying sounds. Its almost like its whistling. Not sure whats causing it though, the frequency in sounds of the exhaust flowing? Seems odd that it doesnt do it at idle, but anything abouve that and its whistling. Hope it goes away. I'll put a couple hundred miles on the car this weekend and see whats up.

 

OMG OMG I have a good idea, dont use Top Teir gas! If you use premium unleaded at some cheap place maybe carbon will build up faster!