Can a new catalytic converter burn out within 1 month due to advanced timing of 14 (spec is BCD) and OX sensor bad? It is a 1994 Plymouth Colt Vista SE 2.4L.
Yes. An excessive amount of fuel being run through the engine creates a RICH condition. And if the engine is unable to burn the fuel it flows into the extremely hot catalytic converter and causes damage to the converter. You will be able to see the inside of the converter melted and clogged. It would also be accompanied with a rotten egg smell.
Catalytic Converter Code
In most cases when the catalytic converter is failing to do its job a P0420 trouble code is stored for OBD II Systems. The OBD II system uses a second O2Sensor to watch the converters efficiency. Since your vehicle is Older than 1995 it is a OBD I system and will not do this. The good news is that you can scan your computer for codes without a scan tool. I would have to guess that you might see a code 51. No need to guess though.
Something to keep in mind is the catalytic converter, unless clogged, will not hinder the performance of the engine. It is installed from the manufacturer as it is required to do so under government requirement.
Since 1975, most vehicles have been equipped with catalytic converters, making the use of unleaded fuel mandatory. All vehicles equipped with catalytic converters have a restricted filler neck opening that will only permit the use of the smaller nozzle used on unleaded gas pumps. The use of leaded gas will not harm the engine, but will destroy the effectiveness of the converter and void your warranty.
A frequent smell associated with catalytic converters is the rotten egg smell, which is unmistakable for anything else. One of the byproducts of the reaction in the catalytic converter is sulfur dioxide (SO2), which is responsible for the odor. It does not necessarily indicate a malfunction, but is extremely unpleasant.