Pulled a P0430 off the OBD port which is a "catalyst Efficiency below threshold (bank 2)". Does this mean that my cat is shot? That's my guess. Help!

Bill

 

it would be a cat or O2 sensor issue...

 

sounds like o2, have you done any work to the truck recently, and after you clear the code does drivability change?

 

could be a hole in the exhaust too.
If your gas has changed formulas drastically recently, detach the battery and let the system drain of power for a good half hour or longer. It'll reset your computer and sensors.

I had to do that with my truck when I came back to florida from Nebraska. I was getting crappy gas milage until I did. Now I'm back to normal. For me it was going from 15+% ethenol and high altitude to e10- and low altitude. still a simple thing to try before spending money.