I check through some of the previous thread and they seem kind of similar but not close enough to my specific issue. 2004 Pontiac Grand Prix. Have a current code of P0420 which I know indicates a potential catalytic converter problem. Replaced both O2 sensors, code still displays. Driving home last night (through hard rain), stopped at a red light and reduced engine power light and charging system failure light came on and the car shuts off. Couldn't get it to crank so I had it towed home. Was able to start it and pull is halfway into drive before it cut off again. Now I can get it to crank but it will cut right back off with the same codes and now the service traction control message is also on. Could all that be caused by a faulty catalytic converter? Am planning on replacement but was looking for a reliable person to do it in my area as I'm not familiar with anyone here as of yet. Any help appreciated. Also am taking my battery to autozone to be tested just in case.