NHTSA (USA)Critical
At a glance
What can fail
The engine can backfire with enough force to damage the air intake system and air cleaner filter on certain medium-duty C-Series and B7 school buses with 7.4-liter gas engines and IMPCO LPG conversion kits.
What the fix does
Dealers will install a redesigned mixer bonnet and air cleaner housing cover, upgrade air induction system connections, and replace the air cleaner filter if needed.
NHTSA Campaign #02V287000 — full official notice →
Summarized — see the official notice for exact wording, dates, and contacts.