As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD - FLT 4234 - AT V1 ON TAKEOFF, SMOKE AFT LAV WARNING ILLUMINATED. CONFIRMED OILY SMOKE SMELL. DECLARED EMERGENCY AND RETURNED TO ORD. LANDED WITHOUT INCIDENT. REPLACED 4TH STAGE SHUT OFF VALVE. OPS CHECK GOOD. PASSED CHECK FLIGHT. AIRCRAFT RETURNED TO SERVICE. (M)