As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT MADE A PERCAUTIONARY LANDING DUE TO A ROUGH RUNNING ENGINE. PILOT CHECKED FUEL AND HEARD A "WOOSHING" SOUND WHEN OPENING THE RT TANK FUEL CAP. PILOT THOUGHT HE CORRECTED A VENTING PROBLEM, TOOKOFF, ACFT LOST POWER ON CLIMB OUT. INVESTIGATION REVEALED PLUGGED FUEL SYS MAIN VENT LINE, PLUGGED VENT INTERCONNECT LINE AT LEFT TANK AND A RESTRICTED RT TANK VENTED FUEL CAP, PN C156003-0101