Thought I was going to have to replace my fresh cat (5000 miles) BUT, thank *** my mechanic is as cool as he is. He said, "well, let me try and clean the injectors and clean out the carbon from the top end and let's see what happens" and voila - My NO compounds dropped from 1400+ into the 400's. Passed for another 2 years.

Makes sense, a bit, when you think about it - If the injectors are dirty, and don't spray enough fuel, that's going to make a locally lean (and therefore HOT) condition that will raise the NO compounds. Only gonna take one or two cylinders to kill your numbers. So if you're struggling with high NO - think dirty injectors as a possibility.

Hope this saves someone else some of the aggravation and expense that it's cost me...

Jonathan

 

Thanks for the info, but I'm going to move this to the General Tech forum, since its not exhaust specific.