After having my Injen exhaust system installed on my G35c6mt, I'm getting a "Fluttering" sound (outside-at rear pipes) at idle. When starting out in 1st gear, it doesn't sound normal, kind of like an exhaust leak. As the revs get higher and go through the gears, the exhaust note sounds normal. Has anyone experiance this & does this sound normal? I've only had it on the car about a week (still smells), but when at idle, the exhaust doesn't seem smooth, as the stock exhaust was. The tach has not changed at idle with the new exhaust. Thanks for your response

 

I think this is normal. the smell will go away in a couple of week. If all the gaskets and bolts was use securely then there shouldn't be a leak. Let it break-in in a couple week and see if it still the same. My friend say it should sound smoother and deeper later on (tone down). Hope this help?

 

Rrowen.
It might be prudent to get the car back up on the hoist to see if there are any leaks, and to retighten all the mounting bolts.
The exhaust sound will change as the exhaust 'breaks in'.
Whomever did the install for you shouldn't mind a follow-up check such as this. It won't take but a few minutes and shouldn't cost anything.
G/L

<font color=red>GSM</font color=red>
<font color=red>GSM</font color=red>
<font color=black>Silverstone Coupe</font color=black>

 

The only problem that I have with mine is that the pipes shifted and rattle on the damn crossbrace. Back to lift for me.

Black G35 Coupe
Injen SES Exhaust
--$riCh$--

 

Thank you for all of your responses. I do need to go back to the muffler shop to pick up my stock muffler this week (saving). I will have them check for leaks and retighten all bolts. No problem of pipes hitting crossmember. I'm hoping that the Injen system just needs to be broken in. The Stillen exhaust on my 300zxTT, has a very different exhaust note at idle.(smooth & deep). I'm hoping this "fluttering" sound and pipe vibration (tips) will go away. I never did an ECU reset. I'm a believer that the brain(s) will adjust to my mods & driving habits over time. Any other opinions is appreciated.

 

the injen exhaust comes with a silencer. makes it a little quiter. if you brought it to a shop, they definitely put it in. have them remove it, as it produces some backpressure, fluttering and it doesnt sound as good! actually, you can take it out yourself with a screwdriver. hope this helps

 

Thanks for your response. Where exactly are the silencers located? I know for a fact that the installer did not remove them. I watched the install of the system. I didn't even know about the silencers, till your post. Since I'm going there this Thurs, I will have them removed. The "flutterting" exhaust note & pipe vibration drives me nuts. I hope you read this for your response.

 

I put in my Injen exhaust the same time as you did and had similar worries (funny smell and resonance) after the install. The smell seems to be getting better, the resonance is still quite loud at low rpm but I have not noticed the flutter you are talking about at idle. I do have an AT coupe so that might be the difference. As far as the silencers go I believe they are now permanently installed on the new version of the exhaust that is out now. Hope this helps you out.

2004 Brilliant Silver Auto Coupe Leather
7 Wire Hyperground
Z-tube/JWT Popcharger
5% Tint Rear 30% Door
Injen Exhaust

 

LuvmyG35C - Thanks for your response. I called Injen & talked to a tech last Thurs. He said that the "fluttering" & resonance is normal. He also said that it does that same thing on their cars at Injen. Also, I ask when the smell will go away. His response, a couple of months! You are right, there are "no" silencers that can be removed. Maybe Auto is different than manuel, in terms of the fluttering sound at idle. Anyway, I leave the system on for a few months, then decided to keep it or get something else and sell the Injen cheap to someone. Thanks