I have a 98 Dakota with a v8 5 speed. Stock cataylic converter and a flowmaster muffler. It has a check engine light on.
I took it to OReilly's and they said it came up the cataylic converter or the o2 sensor were having issues. Cleared the code and the check engine light came on a couple days later.
I have noticed the fuel mileage has gotten a little worse, seems like it is cackling a lot and there is a bit of gassy smell coming out of the exhaust.
I am wondering if maybe the converter is getting a build up(plugged up). Thought about removing the converter and just putting a pipe in it's place. I know it's illegal but I want it to run better and get the little bit of mpgs back.

I guess my questions are:
What do you guys think the problem is?
Does anybody know how it'd affect the truck to remove the converter?
I would really like to eliminate the Cackling. Any Ideas?

Open to any suggestions.
Thanks in advance for the help.

Sean