I've got a friend that brought her 2000 Accord V6 over yesterday. She said it had been running rough from time to time and even dying sometimes. It had a misfire code for every cylinder (1-6), multiple cylinder misfire and egr flow code. When she brought it to me it was running fine. I cleared the codes and waiting to see what comes back.
Isn't it odd to have every cylinder pop up a misfire code? A total EGR falure should even cause that.

Anybody been down this road before and have factual info to share?

Thanks

 

You might want to change the spark plugs if due. Use only the NGK PZFR5F-11. Those are platinum plugs, so they should be changed around 90K miles (look at the interval in the owner's manual).

I think that her accord has coil packs and not a distributor. Inspect cap and rotor if there is still a distributor. I would run some fuel injector cleaner through the tank. I have used Lucas FI cleaner, and it never caused problems.

 

Think about that statement........."replace spark plugs". What is the chance of all 6 spark plugs dropping a missfire instantly the same day. There's a better chance of winning the lotto I think. Spark plugs dont go bad at exactly the same time, or at least I've never seen it happen unless a headgasket blows or something.
I have been reading that there are issues with the 2000 V6 Accords and fuel vapor lock during winter gas (more alky in the gast to prevent freezing in the lines) months. A fuel vapor lock will cause a lean mixture and that would cause multiple cylinder missfires for sure.
I'm still thinking the issue could be related to the EGR fault code.

Does anybody have any factual info on this subject? Has anybody had this exact problem?

 

Clean the EGR port in the intake manifold, since you have an EGR code. Do a search, because that has been covered on here a lot. My friend's was completely clogged and he didn't get the misfire codes you are getting.

I said change the spark plugs if they are due. If the check engine light was on for a while with the EGR port, those misfires on each cylinder could have happened over time. Also, inspect the air filter. Worn out maintenance items can cause all kinds of strange problems.

I have never heard of vapor lock on an accord. Gas freezes well below -100F, and ethanol is added to boost octane rating. Bad gas can cause some strange problems. You never told us how long this was going on, like over multiple tanks of gas? Also how long the check engine light has been on?.

 

Ethanol is added in winter for a couple of reasons.

- The OH group contains some oxygen so it's called an "oxygenated" fuel. A bit less unburned HC during cold-starts.

- More to the point... Small amounts of water in the gas will freeze at -32F because they aren't soluable. Ethanol allows some amount of water to actually dissolve in the mixture, which then the mixture freezing point is well below -32F.