As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RETURN TO FIELD DUE TO A DIRTY SOCK ODOR DURING TAKEOFF. THE ACFT DID NOT PRESSURIZE. OUTFLOW VALVE WAS FULL OPEN. PERFORMED FIM TASK 21-20-00. VERIFIED THE NR 1 ENGINE COMP WASH WAS PERFORMED. PERFORMED DECONTAMINATION ON PNEUMATIC SYS WITH ENGINE IAW AMM 21-20-00-810-803A. NO ABNORMAL ODORS NOTED, OK FOR SERVICE.