So I've had my rx8 for just a couple weeks and now I'm noticing a rattle coming from the exhaust. I've heard that a failed cat can be the cause of this, but is there anything else it could be?

Also if it is a failed cat obviously its much cheaper to just remove the cat and replace it with a mid pipe. Are there any downsides to doing this? Other than the fact it would void my warranty and its less than legal

Any advice is greatly appreciated.

 

you should learn to search before posting.

 

Awesome, anyone else?

 

diagnosing over the internet isn't that simple.
Search around (using your specific symptoms as keywords) and eliminate the possibilities.

 

i have a few rattles that come from my back box. I had a failed cat and all of the insides of it have ended up in the back box. When i apply acceleration i get a few rattles but its fine when idling. I got a new cat now, saving for a better cat back system.

Sounds like you either have a failed cat or have done in the past. How long have you owned it? Has it always done it?

Hope this helps.

My bad, you've had it a couple of weeks. I would get your cat tested. A failed cat is not good for the engine. Don't let mazda scare you into saying its going to be £1500. You can get a just as good one from a website. I will send you the link if you like.

 

Does it sound like this?

https://www.youtube.com/watch?v=mV1PqoxAzfY&feature=youtube_gdata_player

 

Thanks for the replys guys.

Finally broke down and took it to the dealership. My 8 got a engine swap for low compression under warranty just a week ago and the rattle started right after that. The cat was fine but it looks like whoever owned the car before my changed the cat themselves and didnt remove the debris from the failed one. So once my compression levels went up all that blow into my exhaust. Took it to an exhaust place for me and they only charged $35 to clean it out and now the rattle is fixed.

Of course now my car is having the problem where acceleration totally goes dead at 6k rpm sometimes. It was doing this before the engine swap but hasn't since until yesterday. I need to replace the coils and plugs/wires and I'm really hoping that doing that will fix the problem. I'm assuming its not low compression again since i've only had the engine a week.

 

The rattle was Apex seals....

 

How is that possible when he said the rattle came after he got a new engine? Mine rattled when the fans would kick on and when they turned off the rattle went away.

 

Maybe you should let the engine "break in" before getting on the throttle? Lol