I just changed out my primary CAT filter (1R-0750) with
5697 miles on it. I cut it open and it was 90% loaded.
One minor spot of rust on the bottom of the metal
cannister. $10 to replace the filter.

I'll post photos if anyone is interested.

Wow, I would not have expected that. Now you got me wanting to go cut the 1R-0750 CAT filter open that I replaced earlier this year. I had 10,000 miles on it and my truck was running fine when I changed the filter.


I held on to the OEM and CAT fuel filters I changed out as I intended to cut them open. However, they've been sitting in my shed for a few months now. Any opinions on if the humidity in the air will have caused junk to grow in them? If I cut them open now would I still be able to determine how loaded they were when I removed 'em? http://www.dieselplace.com/forum/smileys/Ermm.gif

Maybe it was 80%....... but looks like a reasonable time
to change out our Pre-OEM 1R-0750 CAT is sometime
before 6500 miles.

http://www.dieselplace.com/forum/uploads/Z73_CAT-Cut.jpg