I have a Chrysler Concorde LX 1996 and I took my car for a oit changed and I drove off and then realize that I might need my air filter changed at that time my car was running smoothly. I then went back and had them change my air filter and when I did that just afterwards my muffler started making weird noise like backfiring and spitting black liquid stuff that soon turned to dust and then I noticed that my check engine light would flash and my car would cut off. I took my car to a muffler place and they check my the catalytic converters on my car. On one side the converter was a regular temperature but on the same side where we had the air filter changed the temperature on that converter was very very hot and the temp was very hot from what we were told. What do u thing could be wrong with the engine or emission system or whatever that could be making the engine light flash, cause on side to overheat on the converter, and cause car to back fire.