New 05 mcs in june had performance work done by bay bridge motors (entirely happy with their shop) that included an ultrik header amongst other stuff.
I added a miltek exhaust in august and immediately started seeing
that DAM**D yellow light, comes and goes, mostly stays. The code is
P 0420 "catalyst system efficiency below threshold (bank 1)".

Not too surprising with a free flowing exhaust (cat is hot?). Is this the "nature of the beast" and now must live with the light? change back to stock header for every emmision test. wonder if the code has changed. etc,
Mike

 

See https://www.northamericanmotoring.co...ighlight=P0420

Do a search and you will find lots of references to this problem

 

Chow4us,

thanks for the reply....should have done a search, my bad.

Minimania supplied the header to bbm, just went on tilt when Jacque told
me it was "the nature of the beast".

Minimania is sending another Ultrk header with an improved cat under warranty. Wow, great service.

From what I understand R & R the header should be fairly simple.

 

Glad it worked out.

From reading, it appears the cats supplied by some vendors go bad quickly.

 

I'd look into replacing that cat with one like this:

http://www.atpturbo.com/Merchant2/me...egory_Code=BCS



jlm has one on his MCS with no codes, and I used the same for years on my VW GTI 1.8T without problems. Some manufacturers are using cats that are woefully inadequate at doing what cats do.

 

Thanks for the link Andy,

Minimania is sending the Ultrik with an "improved" cat, I want to give it a shot since it is a warranty replacement. I'll post if it fails and pay the $150 plus for your suggested replacement.
Mike