Hey you guys, I got a 04 wrx and there's a wierd rattle sound coming from what I can tell near the downpipe area. Its a really fainted sound so I'm not to sure what is it. It only makes the noise when the car is at idle and when revving. But it doesn't make the noise when the car is in motion or in any other situation. To exactly describe the sound, it sounds like a metal shaking (not violently, but just mildly shaking and is very faint). All I have done to the car is an Helix Up-pipe/Catted Downpipe, my catback is stock. I'm leaning towards either a possible leak, busted hi-flow cat, or something loose. There is nothing wrong with the actual car, it runs fine...just the noise. Thanks in advance.

 

I had the same problem when I put my downpipe on. It turned out the washer holding the cat back exhaust to the downpipe was vibrating against the metal and was making a rattling sound. I took it to an exhaust shop and had him put on a smaller washer so it would not touch the metal. This could be it.

 

Thanks, hopefully its something simple....I've had it on for quite some time now, at least 5 months. But hopefully its something small...cause the car runs fine no problem. But thanks I'll take a closer look this weekend.

 

Turns out it was the heatshield rattling.... its wierd it never rattled before and all of a sudden it starting to rattle. Its a cobb heatshield....anyone have this problem before? I might think about modifying my stock heatshield to fit my helix downpipe. What you guys think?

 

is everything on the cobb heatshield torqued down correctly? it shouldn't rattle:\. i'd double check the bolts just to be sure.

 

Yeah I doubled check everything, its just the heatshield that's rattling. Though I haven't had a chance to confirm if all the screws are still holding. Maybe one of them is loose or fell out. But I will find out and fix it this saturday for sure.