The minivan has an intermittent problem where the check engine light blinks and the van runs very rough. Began on Monday went away for two days and came back? Why would this occur intermittently?

Thanks

 

Usually when the check engine light is blinking , there is a serious problem with an overfueling condition where the converters could be damaged. That's why it blinks to command your attention.
There should be a code or codes in the computer to direct us to the system with the problem.
If you don't have a code reader you can get the codes usually at no charge from some auto stores like Autozone, etc.
They may even be able to tell you which system is malfunctioning.
Let us know what codes are obtained, thanks.