2012 Honda Odyssey

For several years now, we have misfire issue or code P0304. We continue to change spark plugs cylinders. Both usually last a year or so then they need replaced again. I research the problem, no recall or the like. I did see his report on-line, wondering if it applies to us, Warranty Extension: MIL Comes On with DTCs P0301 thru P0304. Any help would be greatly appreciated.

Dear NHTSA Advisor, Thank you for regarding my request for warranty coverage for the critical misfire and overheating defect with my 2012 Odyssey Honda Engine 3.5L Engine. Odyssey, as described in Honda’s Service Technical Bulletin 13-081. I must reiterate the severity of my situation: the part required for repair is quoted at $7,500.00—and that does not include labor. This amount far exceeds the current market value of my vehicle, effectively making it impossible to afford repairs without Honda’s intervention, it’s aSafety Defect & Known Manufacturer Issue. The misfiring and overheating problems represent major safety risks for my family and anyone who operates the vehicle. This is not routine maintenance, but a substantial defect that Honda has addressed in its own technical bulletin. I have adhered diligently to Honda’s maintenance schedule throughout my ownership. Attached to this correspondence is a PDF containing the complete Service Technical Bulletin 13-081. I am prepared to provide any additional documentation upon request. WARRANTY EXTENSION: MIL COMES ON WITH DTCS P0301 THRU P0304 TECHNICAL SERVICE BULLETIN Reference Numbers): 13-081, Date of Issue: October 08, 2020 HONDA: 2011-13 Odyssey Superceded Bulletin(s): 13-081, Date of Issue: June 18, 2019 Aug 5, 2025 License: Odometer: NOTE: Supersedes 13-081, dated June 18, 2019, to revise the information below. AFFECTED VEHICLES AFFECTED VEHICLES Year Model Trim Level VIN Range 2011-13 Odyssey ALL Check the iN VIN status for eligibility. REVISION SUMMARY Under CUSTOMER NOTIFICATION, outdated information was removed. CORRECTIVE ACTION 2011 Models: Complete diagnosis procedure and if necessary, update PCM software (Procedure A) , replace affected spark plugs then clean pistons and replace the piston rings (Procedure B) • 2012-13 Models: Complete diagnosis procedure, replace affected spark plugs then clean the pistons and replace the pistons rings (Procedure B). No need for software update as 2012-13

vehicle loses acceleration power intermittently. No response when pressing accelerator or when speeding up with cruise control. Pressing the gas harder does not help but the vehicle starts working normally a few seconds later. Dangerous on busy roads. I don't think it is a weak fuel pump because it accelerated quickly after an event

The front valve cover is exposed to extreme temperatures from the catalytic converter mounted next to it. There is nothing to protect the rubber components inside from the catalytic converter's excessive heat which is causing them to fail. The steel components inside the cylinder (e.g., the seal ring) are insulated by these rubber components. When these rubber insulators fail, the steel components are exposed and make contact with the aluminum valve cover resulting in the galvanic corrosion of the aluminum. The most common result I have seen is the deformation of the area where the seal ring is seated (along with holes and cracks). Some people have also suggested possible defects in the casting of the aluminum as a contributing factor (the aluminum is also very thin in that area). Some have suggested the possibility of the uninsulated spark plug arcing, but it seems unlikely to generate enough heat to compromise the aluminum's integrity. The way people have described how the aluminum crumbles seems more indicative of corrosion. There are countless testimonies online of similar defects in Odysseys, Pilots, Accords, and Crosstours with the same engine. I have included a photograph of my damaged valve cover and those of others I have found online.

The contact owns a 2012 Honda Odyssey. The contact stated that the check engine warning light was illuminated on the instrument panel. The vehicle was taken to the dealer for diagnostic testing. The dealer stated that oil was leaking onto the spark plugs. The vehicle was not repaired. The manufacturer was not contacted. The failure mileage was 87,000.

The contact owns a 2012 Honda Odyssey. The contact stated that while driving at various speeds, the check engine warning light would suddenly illuminate and the vehicle would not properly accelerate and would drive very rough. The vehicle was taken to an independent mechanic who diagnosed that cylinder number one was faulty. The vehicle was taken to the local dealer who diagnosed that the oil pressure switches were faulty and needed to be replaced. The oil pressure switches were replaced; however, failure reoccurred. The manufacturer was notified of the failure but no assistance was offered. The failure mileage was 78,000.

The contact owns a 2012 Honda Odyssey. The contact stated while driving 35-45 mph, the check engine warning light illuminated. The contact stated that there was blue smoke coming out of the exhaust pipe and the vehicle was shuddering. The contact continued driving the vehicle to her residence. The vehicle was towed to the dealer who diagnosed that the engine needed to be replaced. The manufacturer was made aware of the failure and advised the contact they could not provide any assistance as she was the second vehicle owner. The vehicle was not repaired. The approximate failure mileage was 141,000.