Q: Rotten egg smell, all lights on dash board are on BUT the check engine light is off.

Simultaneous illumination of "all" warning lights on the dash while driving, when there is no underlying fault, indicates an electrical failure. That failure would have to be diagnosed in a warning light diagnostic. With regard to the check engine light, the bulb could be burnt out and, in any event, a code scanner should be used to see if the PCM has stored any trouble codes that are normally associated with that light, trouble codes that may indeed lead you to a resolution of the engine operating problem (the odor) and perhaps the dash warning lights issue.

Malodorous exhaust, in your case due to the presence of hydrogen sulfide in the exhaust stream, can be due to something as simple as the source of supply (gas vendor) or a circumstance where the catalyst has not had a chance to operate at high enough temperature to burn off and/or fully convert sulfur contaminants in the fuel. The odor is also commonly due to fuel system faults, particularly too rich a mixture. A scan tool should be employed to look at long and short term fuel trims and it might be necessary to scope the firing pattern on each cylinder to see if there are ignition or fuel system faults. If the oxygen sensors on the vehicle are original, they should be carefully tested but after 195,000 miles, I probably would just simply replace them outright as they are way past typical service life. To resolve the issues you are experiencing I would recommend that you request a check engine light diagnostic so an attempt can be made to download trouble codes and, of course, request a warning light diagnostic so that the cause of the simultaneous illumination of the dash warning lights can be identified.