As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(LOG 9416812) AFTER LDG AND SOON AFTER SWITCHING AIR ON TO PACKS FROM APU WE DETECTED A ELECTRICAL LIKE BURNING SMELL IN C/P. FLT ATT SMELLED IT THROUGHOUT PLANE. FOUND OIL RESIDUE ON RT ACM. C/W OIL CONTAMINATION REMOVAL FROM AIR CONDITIONING AND PNEUMATIC SYSTEMS PER B737 AMM 21-00. NO ODORS IN COCKPIT OR CABIN NOTICED.