I usually hate assuming code numbers, but my code list indicates that is a P0401. I'm not familiar with EEC-V/OBD2 diagnostics, so I can't say with certainty, but I expect that could be a DPFE sensor fault. I believe the DPFE sensor is responsible for detecting EGR flow. However, a faulty DPFE wouldn't be the only possible explanation. If it were me, I'd start by getting the code number (might be better off borrowing a scanner from someone), then get a good manual (I've found them at the library or you might see about subscribing to a service like alldatadiy.com) and see what the diagnostic steps are for that code. They will almost certainly ask you to look at certain operating parameters, which is why it would be nice to borrow a scanner so you can look these things up.
I expect somebody here has dealt with this, or has the specific information to help you through this, if you want to wait. I'm sorry I can't be of much more help, but I haven't dealt with the EEC-V system.
