Annoying little light.

My '95 Pickup 22RE 5-speed runs fine, but every 20-30 miles I get a "71" Check Engine Light (EGR System). I've replaced the gas cap, and tested several components according to the factory manual, and haven't found any problem. I did remove the charcoal canister and it may have failed the tests, I'm not sure. But...here's my question: The canister is part of the EVAP system; would a problem with it register a 71 code? Any help, etc. Thanks, Tom.