P0301 on Honda vehicles Cylinder 1 is misfiring

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 Honda filed with NHTSA whose summary names P0301. Quote the document number at the service desk — it is a diagnosis the maker has already written down.

• A18-114 Service bulletin
  2018-10-22 · Engine And Engine Cooling
• Service bulletin - Under certain circumstances, the vehicle may experience driveability concerns, which may result in DTC's P0300 (Random Misfire Detected), P0301 (No. 1 Cylinder Misfire Detected), P0302 (No. 2 Cylinder Misfire Detected), P0303 (No. 3 Cylinder Misfire Detected), P0304 (No. 4 Cylinder Misfire Detected), or P0172 (Fuel System Too Rich) to set.
• A18-124 Service bulletin
  2018-10-22 · Engine And Engine Cooling
• Service bulletin - Under certain circumstances, the vehicle may experience driveability concerns, which may result in DTC's P0300 (Random Misfire Detected), P0301 (No. 1 Cylinder Misfire Detected), P0302 (No. 2 Cylinder Misfire Detected), P0303 (No. 3 Cylinder Misfire Detected), P0304 (No. 4 Cylinder Misfire Detected), or P0172 (Fuel System Too Rich) to set.
• A18-114 Service bulletin
  2018-12-07 · Electrical System — Software
• "Service bulletin - Under certain circumstances, the vehicle may experience driveability concerns, which may result in DTC's P0300 (Random Misfire Detected), P0301 (No. 1 Cylinder Misfire Detected), P0302 (No. 2 Cylinder Misfire Detected), P0303 (No. 3 Cylinder Misfire Detected), P0304 (No. 4 Cylinder Misfire Detected), or P0172 (Fuel System Too Rich) to set."
• A18-137 Service bulletin
  2018-12-21 · Electrical System — Software
• "Service bulletin - Under certain circumstances, the vehicle may experience driveability issues which may result in DTCs P0300 (random misfire detected), P0301 (No. 1 cylinder misfire detected), P0302 (No. 2 cylinder misfire detected), P0303 (No. 3 cylinder misfire detected), P0304 (No. 4 cylinder misfire detected), or P0172 (fuel system too rich)."
• A18-137_V2 Service bulletin
  2018-12-22 · Electrical System — Software
• "Service bulletin - Under certain circumstances, the vehicle may experience driveability issues which may result in DTCs P0300 (random misfire detected), P0301 (No. 1 cylinder misfire detected), P0302 (No. 2 cylinder misfire detected), P0303 (No. 3 cylinder misfire detected), P0304 (No. 4 cylinder misfire detected), or P0172 (fuel system too rich)."
• A18-137 Service bulletin
  2019-01-12 · Equipment — Appliance — Air Conditioner
• "Service bulletin - Under certain circumstances, the vehicle may experience driveability issues which may result in DTCs P0300 (random misfire detected), P0301 (No. 1 cylinder misfire detected), P0302 (No. 2 cylinder misfire detected), P0303 (No. 3 cylinder misfire detected), P0304 (No. 4 cylinder misfire detected), or P0172 (fuel system too rich)."
• A23-026 Service bulletin
  2023-03-14 · Engine And Engine Cooling
• Service Bulletin - Under certain circumstances, the vehicle may experience driveability concerns. This may result in the following DTC’s to set: • P0300 (Random Misfire Detected), • P0301 (No. 1 Cylinder Misfire Detected), • P0302 (No. 2 Cylinder Misfire Detected), • P0303 (No. 3 Cylinder Misfire Detected), • P0304 (No. 4 Cylinder Misfire Detected), • P0172 (Fuel System Too Ric
• AEBM06172025901 Other
  2025-06-17 · Engine
• Dealer Message - Piston ring effectiveness may be reduced due to excessive wear and oil sludge build-up, which can cause oil to adhere to the spark plug, potentially leading to carbon fouling and misfire triggering DTCs P0301 through P0304 and cause the MIL to come on.
• A25-061 Service bulletin
  2025-07-18 · Engine
• Service Bulletin - The piston ring function deteriorates due to ring wear and sticking from sludge. Oil from the crankcase adheres to the spark plug leading to carbon fouling and misfire. This can set DTCs P0301 No. 1 cylinder misfire detected, P0302 No. 2 cylinder misfire detected, P0303 No. 3 cylinder misfire detected, P0304 No. 4 cylinder misfire detected, and cause the MIL to come on.
• ONL6Z6072025 Other
  2025-07-29 · Engine
• Owner Notification Letter - the piston ring function can deteriorate due to ring low wear toughness and sticking from sludge. Oil adheres to the spark plug leading to carbon fouling and misfire. This can set DTCs P0301 No. 1 cylinder misfire detected, P0302 No. 2 cylinder misfire detected, P0303 No. 3 cylinder misfire detected, P0304 No. 4 cylinder misfire detected, and cause the Malfunction Indic
• A21-007 Service bulletin
  2022-06-01 · Fuel System, Gasoline
• Service bulletin - The MIL comes on with DTC P0300 (random misfire detected) or P0301–P0304 (cylinder misfire detected). Carbon buildup on the intake valves may be affecting combustion.
• A21-007 Service bulletin
  2023-06-02 · Engine And Engine Cooling
• Service Bulletin - The MIL comes on with DTC P0300 (random misfire detected) or P0301–P0304 (cylinder misfire detected) due to carbon buildup on the intake valves may be affecting combustion.

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