Most importantly, do not drive the car with a Check Engine light flashing. That has the potential to turn a relatively minor problem into an expensive one very quickly.
When the Engine Computer detects a problem, it sets a diagnostic fault code, and if that problem could adversely affect emissions, it will turn on the Check Engine light. You can get a general idea of the severity of the fault code by how the light acts. If the problem is intermittent and the light goes off while you're driving, that is the least serious type of problem. If the light only goes off after you stop and restart the engine, that's a little more serious. If the problem goes away temporarily but the light is always on anytime the engine is running, that's still more serious. The most severe problems result in too much raw fuel going into the exhaust system where it will overheat and destroy the very expensive catalytic converter. Those are indicated by the flashing light. That means stop the engine as soon as you can do so safely. Don't drive it to a repair shop like that. Damage can occur in less than a mile or two.
Since you could smell the overheated catalytic converter, it may be damaged already. The first thing you should do is have the fault codes read and recorded. Many auto parts stores will do that for you for free, but you must understand they're in the business of selling parts and that's all they know. Fault codes never say to replace parts or that they're bad. They only indicate the circuit or system that needs further diagnosis, or the unacceptable operating condition.
You didn't list the engine size or mileage so I can't make any recommendations related to that. Normally when you have an engine running problem, we need to know which engine you have. If the mileage is to the point where the spark plugs and wires can be expected to be worn out, that can cause all of the problems you described. That is a case of lack of maintenance leading to bigger problems. The days of regular tune-ups are gone so we tend to get complacent and forget that there's still some parts that need regular replacement.
Tuesday, November 25th, 2014 AT 10:30 PM