engine shuts off

Have you tested or replaced your auto shutdown relay? Because this code 42 states that there is a problem with the ASD relay or circuit, which feeds major components like the injectors, etc. ASD relays do go out, as does any other relay eventually. I have replaced several. here is a site that will have the location of the relay, it is usually in the under hood power distribution center http://bit.ly/mitchell_repair_manuals_online

check the egr valve and then the cat conver

It sounds like what I went through with my 1998 Chrysler Sebring (2.5L V-6). It turned out the Cam Position Sensor and the Crankshaft Position Sensor needed to be replaced. Faulty or intermittent signals from either of these will activate the Automatic Shutdown Relay.