Honda Accord 2003 — technical service bulletin
Bulletin 604 · NHTSA communication 10014141 · issued Jun 16, 2004
Technical service bulletin
communication type
Engine and Engine Cooling
component
2003
model years
2
vehicle entries
Official summary
Update ecm/pcm for diagnostic trouble code p0420, catalyst below threshold. *nm
Vehicles covered
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.