My car keeps turning off while I'm driving eventually it turns back on when I try starting it a few times... my check engeine light turned on so I hooked up the computer and it said code420... I looked it uo and it says its my catalytic converter and o2 sensors I have a 98 honda accord lx and have recently replaced my o2 sensors about 6 moths ago but not my catalyic converter... Could it be why my car turns off while I'm driving do I have to replace both can I do it myself

Do you have a torch to properly attach the catalytic converter to the exhaust system? If no, then take it to a shop who has this. Did you check the coil as well to make sure this is good?

It may be something else altogether; e.g. a bad Ignition Control Module (ICM) or coil. A failing ICM or coil can cause incomplete combustion, loading the catalytic converter with unburned gasoline. The cause may be a failing ICM or coil and the effect is a fuel-ladened catalytic converter. I would replace the ICM and coil, first, and see if the situation improves. Converters are usually long-life items. If you decide to replace the ICM, be sure to apply silicone heat transfer compound to the back of the new ICM. This is, potentially, a dangerous situation, where unburned gas in the converter can suddenly be ignited and blow the exhaust system off the car. I would replace the coil at the same time. These problematic components should be replaced every 120,000 miles or 10 years, whichever comes first.