Where did the name "testpipe" come from? Or why do they call it that? I can see the pipe part, but I don't see where test comes into it.

 

good question. probably has something to do w/ race track times....wild guess

 

in the mid 70's when cat. convertors first came out, they were known to clog easy. Esp. since leaded gas was still available. You could buy a "testpipe" to mount in place of your mostly dead cat. convertor to see if normal engine performance returned.

The other test method was to drive the crap out of the car, stop fast, and look underneath the car. If the cat. was glowing CHERRY red, it was dead/clogged.

 

BTW, I guess I've shown my age with this post.