What is going on with my van?

A flashing Check Engine light indicates the most serious condition. It means too much raw fuel is going into the exhaust system and is going to overheat and damage the catalytic converter. You're supposed to stop the engine right away to prevent that from happening.

Any time the Engine Computer detects a problem it sets a diagnostic fault code, and if that problem could adversely affect emissions, it must turn the Check Engine light on. The place to start is by having the code read. Many auto parts store will do that for you for free, but you must remember that 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. There are well over a thousand potential fault codes so there's no way to guess on what it will take to solve the problem. Some of those codes get pretty specific too so we need to know the exact code number, not just the generic description.

Have the fault codes read. That will tell us where to go next.