tomcheney

Don't know if anybody else has suffered this from this but noticed a rattle coming from My S about 1k ago (thought it might be the CAT heat shield working loose). Have just had the car service and the dealer has informed me that the rattle I have been experiencing is the Catalitic converter breaking up inside!!!!!

He informed me that he has not seen this on an S. Mine has only just covered 63k so I was rather suprised at this, my mot isn't up till April so no great rust to get it changed (apart from the annoying rattle!!!!) however was shocked at the price of the replacement part from Honda at

MikeyCB

If I had to replace my cat and pay out of pocket, I'd go for an aftermarket cat. More likely would be I'd go for a testpipe.

SpitfireS

Happened to me too.
You'll find more posts about it after a search
It's not so much the cat breaking-up, but the core becoming loose in the housing.
Be carefull not to let it rattle too long as it may damage the O2 sensor.
(if the second core downstream is rattling)

The OEM cat allready is pretty high flow with a metal foil thickness of only 0.05mm.

I found an as-good-as-new OEM cat on Sk2i

Top one is the "new" MY04, bottom is my old MY00.
Notice the different spot for the O2 sensor.
Yellow arrow is direction of flow.

S2kracka

Testpipe time!

2poor2mod

i got a used one in my attic, but with shipping might be a bit much. if it were me i would go for the test pipe

cdelena

The core coming loose and trashing the O2 sensor is a pretty common failure. Emission systems should be covered for an extended period but if it is too late I would look for a used cat... enough people pull them off in this country that they are not too hard to find.

Emil St-Hilaire

Test pipe FTW.

tomcheney

Cheers for all your advice have purchased an my06 cat from a breaker here in the uk.

brimstone

Same thing happened to me. I have an 06 at ~26,000kms (+16,000mi), getting it changed under warranty. Its taking a while (10 days left) to get over here, the mechanic said I could drive the car in the meanwhile, but that I would notice some power loss. Seems reasonable.

A friend just bought herself an new Audi TT coupe, with a 2.0 turbo (~200bhp), its an automatic. I wasn't able to really pull away from her in a straight line, shifting at redline each time, not getting any CDV or VSA action (proper traction/shifting). I then lost her when the road got twisty, but it made me wonder... could the "blockage" in the cat cause a 40hp temporary power loss (to be rectified with the new cat installation)?

The mechanic noted that the problem could've been caused by a sudden contraction, for example when you drive over a pool of water after the cat is hot, it gets splashed... you get the picture.

jimknapp

Don't know about the UK, but in California the emission system must be warrantied for a Loooonnnggg time. Cats on my Ferrari were going to be $3500 each until I found out they were covered for 7 years. As it was I had already taken one out and taken it to Catilyzer in San Diego and had it re-built for $450. But a similar Toyota one was on the bench for $150.

All y'all might look for a catalyst re-builder for these issues.

Keep the shiny side up.

Jim