Experiencing a misfire in your engine can be frustrating, especially when the check engine light illuminates with an OBD2 code like P0305. For my Honda Odyssey, this code pointed to a cylinder 5 misfire. Determined to tackle this issue myself, I embarked on a DIY repair journey that, while educational, didn’t exactly go as planned. This is my story of diagnosing and attempting to fix a P0305 code, which ultimately led to more questions than answers.
The saga began with a visit to my local Honda dealership. Speaking with a service advisor, I described the P0305 error and the preliminary steps I had already taken. Based on my description, the advisor suspected a fuel injector problem. This suggestion shifted my focus away from initial thoughts of compression issues and towards the fuel system. The advice led me to decide to replace the fuel injectors on bank 2, which in my Honda Odyssey corresponds to cylinders 4, 5, and 6.
Equipped with this new direction, I headed to Napa Auto Parts and picked up three new fuel injectors (PN: 2-38868). Anticipating potential intake issues, I also grabbed a Fel-Pro plenum/intake gasket set (PN: MS 96409-3). Just in case compression testing became necessary after all, I borrowed a compression tester. Rounding out my toolkit, I added Permatex Ultra Black RTV sealant, CRC throttle body cleaner, and a torque wrench – all the essentials for a hopeful DIY fix.
Back home, the disassembly process began with disconnecting the battery and various wire connectors. I systematically removed lines, hoses, and the air cleaner assembly to gain access to the intake manifold. Removing the plenum revealed the upper intake manifold, bringing me closer to the injectors. However, I encountered a snag with a vacuum line stubbornly stuck within the air cleaner intake flow hose. In my efforts to remove it, the vacuum line outlet began to tear – a minor setback but a sign of potential complications ahead.
