Drive Accord Honda Forums banner
1 - 1 of 1 Posts

05 Accord Coupe V6 6MT
11 Posts
Discussion Starter · #1 ·
I've got a 2005 Accord Coupe V6, and shortly after purchasing it I had my check engine light come on one day so I checked the codes, and saw that I was having cylinders 1-5 misfiring plus a random misfire and an EGR valve code.

1. Having a seized EGR valve (stuck open or closed) or plugged port can cause the ECU to think the engine is misfiring. So I pulled my EGR valve and cleaned it really really well. Then cleaned out the EGR port and cleared the codes. This fixed my EGR code, but the misfires remained.

2. I pulled all my coils and boots to find they had been packed with dielectric grease (as i assume the previous owner thought it would help contacts, but in these cars the spark plugs get very hot and cause the grease to run down onto the outside of the plugs leading to cracking and dirty plugs with worse contacts), then I cleaned all the boots, changed all the plugs which had silicone lube on them (i don't know why), and put it all back together.

This corrected all of the misfires accept for a misfire in cylinder 5. None of the misfires were actually noticeable when driving. The misfire counter would show the misfire, but you would never guess its there. I tried swapping around the coils and boots to see if the misfire would move to the cylinder with the boil/boot from cylinder 5, and it didn't.

After some research, I found out there is an ECU update for this car, and I assume its never been done (as the last owner did terrible maintenance). This update should widen the parameters for what classifies as a misfire to the cars computer therefore not having the code come up.

Ill take the car to the local Honda dealer, and get them to run the update, hopefully fixing the final misfire.

No misfires and im a happy man. :banana::banana:
1 - 1 of 1 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.