Thanks for the input, John_AZ. I have no knowledge of the amount or types of metals in one Bosch O2 sensor versus another; they looked identical to me except for the connector, and that's what this thread was originally about.

As for the use of solder versus crimped connectors, I think there's enough satisfactory real-world experience to justify the use of solder. It's a matter of personal discretion and shouldn't be discouraged simply because it's not the approved or popular method. It works fine.

+1 on the 15725.

http://forums.pelicanparts.com/porsche-924-944-968-technical-forum/514367-test-results-new-universal-o2-sensor.html

Works great and backed up as the correct sensor by a Bosch engineer over on the 'list. It comes with posi-lock splice connectors that are a piece of cake to use and are waterproof.