I have a 2004 isuzu Axiom. I have a check engine light on. I'm reading two codes, P0420=cat. converter and P01249 which I'm not sure what that one means.

The car would stall while driving it and losing power it seems like. Every time I drive it it seems to run and run decent but there's some hesitation due to the cat. converter and one of the O2 sensor. But it still cranks over and runs good for me. I got 3 kids and only one car these days. My wife drives it, it will act up on her. What it will do for her is lose power to the point where it will start and shut right back off. It won't even idle. Just last night that happened to her on Interstate 95. It will start and put for a few seconds and I would try to tap the gas peddle a couple times and It wouldnt raise RPM's and then stall. I am mechanically inclined but this is my first time owning an Isuzu. On the side of I95 I popped the hood and disconnected the positive battery cable for about 5 seconds. I tightened it back up and I started the car. It started and kept an idle. The check engine light went out and ran better than before. I got to the hospital to drop my wife off cause we just had a new born. And I shut the car off. Walked her in and when I came out to leave and go back home I started the car and the check engine light came back on before I put it in drive. I drove it home with no problems though.

Does anyone have any clue what my problem could be?
Very appreciated.