• Protip: Profile posts are public! Use Conversations to message other members privately. Everyone can see the content of a profile post.

Melting Catalytic Converters?


Experienced Member
13 May 2000
Lake oswego, OR
Every time I pull off the track my exhaust has a rattling noise coming from the muffler. It usually goes away after a few days of normal driving, so it didnt really bother me, except this last time it didnt go away. I went to a muffler shop and removed the resonated tips (I thought they were rattling) and when I revved the engine to blow out some of the crap that was in the tips, out came 5-10 small (1/4" - 1/2") size peices of my Catalytic converter. Do any of you have this sort of problem? Is this a sign of my car not running right? What kind of solution is there for this problem? I am assuming that if I continue like this I will need 2 expensive cats come emissions time in a year or so.
I suppose its *mostly* stock.
I have an RM CAI, and a Supertrapp Exhaust on full open (22 discs)
Also a Dali Clutch and Flywheel.
The rest are Suspension and Brake mods..
A rich mixture and can make the converter run extreamly hot to the point where I have seen them melt, creating enough back pressure where the car could start, but only run a few minutes. This was an extreme case, but you might have reached a point where your converter was slighly damaged and is now slowly falling apart.
How do I avoid getting a rich mixture?
I am running the stock ECU, so it shouldnt run too rich should it?
I am installing a MOTEC controller soon..will that take care of the problem?