As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED A STRONG ODOR OF SMOKE IN THE COCKPIT AND CABIN UPON TAKEOFF. THE CREW RETURNED TO IAH AND LANDED WITHOUT INCIDENT WHERE MAINTENANCE PERFORMED TROUBLESHOOTING TO DETERMINE THE ORIGIN OF THE SMOKE. THE ENGINE AND BLEED SYSTEMS WERE RUN AND THE SMOKE ODOR COULD NOT BE DUPLICATED. THE DISCREPANCY WAS CLEARED AND THE AIRCRAFT RETURNED TO SERVICE.