So I've posted a few days back about my exhaust suddenly sounding more muffled and having less "infiniti" growl. Everything is stock besides looks. Its an 04 AT. Happened randomly one day after I started the car. Car started sounding like an '88 honda belonging to a ricer. No idea what has caused it ( no, no bananas in the tailpipes, i checked ) Originally thought it was the cats but after doing more research I think I narrowed it down to the muffler. No rotten-egg smell, no rattling noises, and no power loss (not that I know of). Gas mileage might've gone down a bit unless I've just been heavy footing it just to hear the problematic exhaust in hopes of it going away. Just need to be sure thats what it is before I go ahead and replace it. Haven't had time to take it to the shop to get inspected cause my shops booked till next week. You have to really listen in the video cause it didn't quite come out as accurate as it sounds in person, but you'll get the gist of it. All help is appreciated.

Link to original thread
https://g35driver.com/forums/g35-cou...y-exhaust.html

Video

 

Only way to tell is to take it to a shop but I'd blame the cats and have them checked out before I wasted $$ on a muffler. You wouldn't believe how much restriction there is in our OE cats....
Gary

 

Yea true but could it really be the cats even though its not giving any obvious signs that it could be them?

 

I've seen cars quit running due to plugged cats and no rotten egg smell. A coupe tanks of low quality gas and we're DIW!
Gary

 

idk what happened but it definately sounds gross

 

Dang, sounds like something is suffocating the oem exhaust sound. Good luck, makes me miss the oem exhaust sound sometimes..

 

It sounds beyond gross. Makes me quiver when i hear it while driving. The thing is nothing happened at all. The only thing i can think of is that i filled up at a Shell gas station that i never fill up at. I filled up 19.500 so i was LOW on gas. Always fill up super so im guessing that Shell was s*itty? The thing is it started happening 2 days AFTER that fill up so at first i completely ruled out that as a probable cause. What do you guys think?

 

It's not the best quality audio lol, but it sounds like it could be a few things. It could be your cat's or muffler. However, it sounds like you could have fouled/fouling plugs too. I only say that because of the "spattering" sound when the revs fall back down. That sound is normal when revving the **** out of it, but not normally when you're taking it easy like that. Just my .02, but that may not be worth much lol. GL

 

Yea it was a crappy cell phone video so it definitely wasnt the best quality but you can pretty much make out what im talking about. Now the big thing is that im driving back up to new york from north carolina tomorrow which is roughly 700 miles. Do you guys think itll be alright to drive with this and fix it once im there since i know a good shop? Will it damage the car in any way or could it die on me? That wouldnt be so fun..

 

You know what, I just rewatched the video with my Beats headphones and it sounds like just a loose flange or hole in the muffler. However you only hear it on the down rev which make me think it is vibrating metal on metal. Take it into a muffler man and have them take a look at it. They will look at it for free and give you an estimate on what it'll take to fix it. They also do a lot of real services too so they should be able to tell you whats wrong no matter what.

 

Yeah did you run over anything recently that could have put a puncture in your exhaust? It sounds like a hole in the exhaust to me or something is possibly loose...but can't really be sure unless I heard it in person.

 

Nope thats the thing. I avoid potholes at all costs. Havent run anything over, never scraped the bottom, NOTHING at all. Yea I think it might be a hole, but then again it just happened randomly one day when i started the car. Cars been babied and is pretty much a garage queen (even though that doesnt mean much). So do you guys think ill be okay to drive 700 miles tomorrow?

 

It sounds more annoying than anything. I'm sure youd be fine on your trip. Of course, if it's your cats and they're clogged or restricted in some way, you may get shitty mileage. Just watch for check engine lights, if there are none then you're fine. EVERYTHING has a sensor on our cars and the ecm will know if theres a problem.

 

is it the muffler that gives our car their sound? or is it the engine? or a combination of both?

i wonder what a v8 would sound like with our muffler...