As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THERE WAS AN ACRID SMELL COMING FROM THE DUCT SYSTEM BOTH IN THE CABIN AND COCKPIT. SWAPPED THE BLEEDS AND WAS STILL CONTINUED TO SMELL. THE INITIAL ODOR WAS RUBBERY BUT MORE OF AN ACRID KIND. REMOVED CONDENSER BAG WITH NEW. COMPLIED WITH OPERATIONAL CHECK OF THE AIR CONDITIONING SYSTEM IAW MM 21-51-13-000-801, 21-51-13-400-201 AND 52-41-00-410-801. OPS CHECKED SATISFACTORY, WITH NO ODD ODORS PRESENT.