As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CABIN ODOR REPORTED IN COCKPIT BY FLIGHT CREW. EMERGENCY DECLARED AND RETURNED TO DEPARTURE, LANDED WITHOUT FURTHER INCIDENT. THE AIRCRAFT WAS GROUNDED. MAINTENANCE ACCOMPLISHED CABIN ODOR, SMOKE WORK CARD IAW MCM 05-96-70, AND FOUND THE RIGHT A/C PACK OVERHEATING. MAINTENANCE REPLACED RT A/C PACK IAW AMM 21-51-04.