Secondary Cats
 

Just a quick question here; I recently replaced my primary cats and they were definitely shot. One had a piece of the core drop out as soon as it removed the other would move if you shook it. That said, if the primary cats were in such bad shape, what is the probability that the secondary cats are broken? Have people in the forum found that was the case, if your primaries are bad so were the secondary cats? Other question is what are they there? Is it better to get the bypass kit? Does anyone know if removing the bypass will not pass CA Smog?

I removed my secondary cats but I am in Texas. I imagine you might have an issue in California but hopefully someone from there will chime in. Try a Google search that includes this forum, I believe this issue has been discussed before.

I'm in San Diego (986 S): I pulled the secondary cats years ago, and have passed smog many times. These days the tech only plugs in the obd 2, and the nox etc numbers are a fraction of the limit. I don't know what Porsche was thinking.

Hasta La Vista - Secondaries
 

Thanks for the replies based on this info and the reported pick up in performance (8HP) they are gone:)

Nice! I think deleting them makes a very noticeable difference IMHO.