P0442 on Buick vehicles A small leak in the evaporative emissions system

A model year is listed because the code is named in its own record — a bulletin filed against it, or an owner’s complaint about it — not because every one of these vehicles sets it. Counts are documents in NHTSA’s files, not failure rates.

Owners’ own words, scrubbed of anything identifying. Unverified reports filed with NHTSA — what was said, not a finding that it was true.

Bulletins and campaigns Buick filed with NHTSA whose summary names P0442. Quote the document number at the service desk — it is a diagnosis the maker has already written down.

• 21NA124 Service bulletin
  2021-05-25 · Electrical System
• This service bulletin provides diagnostic tips/steps on testing for possible EVAP leaks in the system to correct a customer concern of an MIL Illuminated with DTCs P0442 and/or P0455 Set.
• 21NA124 Service bulletin
  2021-05-25 · Fuel System, Gasoline — Storage — Evaporative Emissions — Canister
• This service bulletin provides diagnostic tips/steps on testing for possible EVAP leaks in the system to correct a customer concern of an MIL Illuminated with DTCs P0442 and/or P0455 Set.
• 21-NA-124 Service bulletin
  2022-12-14 · Engine And Engine Cooling
• This service bulletin provides diagnostic tips/steps on testing for possible EVAP leaks in the system to correct a customer concern of an MIL Illuminated with DTCs P0442 and/or P0455 Set.
• PIE0528 Service bulletin
  2019-07-11 · Engine And Engine Cooling
• Some customers may note a Check Engine Light related to the evaporative emission canister performance. Technicians may find the following DTCs set: • P0442 • P0455 • P0446 • P0449 • P0498 This engineering informational bulletin is requesting information from the field on warranty parts for complete canister assemblies that apply to the DTC codes specified and has leak conditions. Engineer
• PIT4943D Service bulletin
  2015-12-09 · Engine And Engine Cooling — Exhaust System — Emission Control
• This Preliminary Information communication provides information to the technician about vehicles that have a Service Engine Soon Malfunction Indicator Lamp. Technician may find Diagnostic Trouble Code P0442. Technician will need to review Techlink article from May 2013 titled "Using the Evaporative Emissions System Tester" Technician will need to follow these steps to help diagnose the issue. Firs
• PIP5862 Service bulletin
  2022-07-28 · Engine And Engine Cooling — Exhaust System — Emission Control
• This Preliminary information communicates the possibility of dtc p0442 advising dealer to be sure the evaporative emission system is leak tested as directed through service information and replace evaporation emission canister if no issues are found.
• PIP6038 Service bulletin
  2025-01-22 · Unknown Or Other
• This Preliminary information communicates to the technician the repair directions should they encounter DTC P0442.

A stored code names the test that failed, never the part that caused it. The record above is what Buick and its owners have filed about it; the code’s page across every make has the whole file.