I have done as much research as possible on this topic and it's time to ask other real-world owners. WHERE are you finding 50-state approved (or California) replacement catalytic converters for the one-year (1995) 540i Sport 6-speeds? They are different from 1994 540iA and extremely ($3900) expensive from BMW. At 187K, I finally need to replace my pair. Everything else has been tested and replaced. To pass CA smog, I've got to replace the cats., but try finding them! I'd prefer not to weld in universals. First post, thanks.