As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FUEL AND EXHAUST ODOR THROUGH THE PACKS AFTER APU START AND BLEED SWAP. RAN AIR CONDITIONER SYSTEM IAW CRJ MM 21-51-00. INSPECTED APU COMPARTMENT, NO LEAKS FOUND. SYSTEM OPERATED NORMALLY WITH NO ODOR OF FUEL OR EXHAUST IN COCKPIT AND CABIN AREA.