Tengoku

The first video you can hear the rattle underneath the car when the engine is idling.

[media]http://www.youtube.com/watch?v=_eOLFogynHM [/media]


I went underneath the car and hit the cat with a rubber mallet trying to see if it is the same noise, Is this the same noise?

[media]http://www.youtube.com/watch?v=F4q1To09-4c [/media]


do I need a new cat?

Thanks in advance!

iheart9krev

It sounds like it to me unless the cat heat shield or something else is loose. Sounds like the honeycomb rattling inside. Do u feel loss in power esp in vtec? Started noticing mine going bad when there was a noticeable decrease in power above 6k rpm and it eventually threw a cell for "Catalyst system Efficiency Below Threshold"

Purchased a berk 70mm hi-flow cat and passed smog 3 days later...barely.

chef-j

Sounds like yur cat core melted down. Can't really hear clear since your exhast so loud. Simply, just un bolt the cat and look at inside before you orde any atermarker cat/TP.

Tengoku

it says that the Berk 70mm hi flow cat is for off road use in CA. How did you pass smog with it? and I think your sig says you are from the bay area?

SpitfireS

Check your cat before the shifting core damages the sec O2 sensor - they are expensive.
The OEM cat allready has a metallic core, and is pretty high flow IMO.

BMX RACR

Sounds like the catalyst honeycomb is broken apart and rattling around, you need a new cat. The more you drive it like this the more damage you`re gonna do.

chuhsi

if your cat is really broken, i believe it's covered under an 8 year 80k emissions warranty.

iheart9krev

yes, berk only supports it for offroad use only because it wont pass visual inspections. But it will pass the sniff test. I was right at the cutoff for HC though. it all depends on how picky your tester is on the visual. U can try to hide your hfc with the cat heatshield cover. PM me if u need more info.

scareyourpassenger

Mine made a similar noise and then it went away. I was sure the cat was busted as the secondary sensor went bad. The dealer replaced the sensor and didn't see that the core shifted and took out the sensor like I had thought.

I am still under warranty so I didn't push them to inspect the cat but I know I will when I have some free time

whiteflash

Asura