The check engine light came on, dash readout says "restricted performance"

Your fuel fill is likely not a concern. Have a diagnostic test performed to see what trouble codes are stored in the engine's computer; this will give guidance on how to proceed.

Have it scanned by an OBD code reader. I had the same lights come on and the code said that the air intake duct sensor went off and that the 4 banks were running lean. It turned out to be the pressure release hose that disconnected from the nozzle on the supercharger.