Complaint 2117857

Complaint Summary

FUEL/PROPULSION SYSTEM

Owner Narrative

A poorly designed engine leads to misfires even after proper maintenance, increasing the chances of a crash. On Monday, May 12th, 2025, the MIL indicator came on and began flashing while I was driving. The engine began to misfire so violently that the vehicle was nearly undriveable; acceleration was dangerously poor. After I got home, I used a OBD-II code scanner and pulled a "P0301 - Cylinder 1 misfire" DTC. Then, I did some research, and found that a poorly designed engine causes oil to burn inside the cylinders and foul the spark plugs. I inspected the spark plugs and found multiple fouled plugs, specifically on the cylinders on which Honda's Variable Cylinder Management activates on, cylinders 1-4. I replaced all six spark plugs, and the issue went away, as expected. Photos of the fouled plugs are attached. Honda is aware of this problem, as it recently extended the warranty of the engine in this vehicle. I received a letter on July 31, 2025, titled, "Warranty Extension: 2013-15 Pilot & 2013-17 Odyssey MIL Comes on with DTCs P0301 thru P0304." (See uploaded file.) Spark plug inspection and replacement is part of the repair, in addition to a partial engine rebuild and software update. However, the warranty extension only applies *after* the misfiring has started, which is no help to the safety of this vehicle, as the issue can start at any moment while driving. Furthermore, the warranty extension only adds an extra six months to many of the affected vehicles. Therefore, any vehicle this extension applies to is an unsafe vehicle unless the safety issue already occurred and was repaired. If the issue presents itself after this time period, the owner is left with an unremedied vehicle and with an expensive repair bill.

Owner-submitted narrative on file with NHTSA. Complaint narratives are self-reported and have not been verified.