As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
OUT OF 12,000 FT SMELLED A PLASTIC BURNING SMELL FOLLOWED BY SMOKE AFT LAV EICAS FOLLOWED GRH PROCEDURE SMOKE AFT LAV RETURNED ORD EMERGENCY DECLARED-C/A-C/W FIM TASK 21-22-00ABNORMAL SMOKE/ SMELL AFTER MAIN ENG COMPRESSOR WASH, GROUND RAN BOTH ENGS AND BLEED SYS AS PER CRJ MM TASK 72-00-00-100-801 UNTILL ALL FUMES NO LONGER PRESENT NO DEFECTS NOTED.