I have a 2000 Honda accord ex v6 and its been a nightmare since I had it, took it to three mechanics no one could figure out my problem I've changed so many things I've lost count, it won't start after I drive it for about 15 minutes of driving and it takes about and hour to start back up after its been off for that time, but it starts right up after I drive it shut it off for 5 minutes, it's weird. I see a lot of people have the same problem but no one can diagnose it, I even took it to my local Honda dealer and they said it was the PCM and fuel pressure regulator, changed that and nothing, during the whole time I had problems with it, the only check engine light I had was my evap canister, changed that but still the problem happens. But today I picked it up from getting inspected and my new codes I have are p0301-p0306 which the mechanic said are my ignition coils, but they come 50 bucks a piece and I don't wanna buy all 6 if I don't have too, could it be just one that's making the rest misfire or should I change my all 6? Also to pass emissions, my catalytic converter is coming up with a code and he also said its the coils that made it go bad, cause I changed my cat about 3 months ago to try and fix the problem, I know it could just be a o2 sensor but I'm so frustrated with this car and I don't know what I should do. Please help. Thank you

 

P0301 is a misfire detection code for cylinder 1 and a P0306 is for a cylinder 6 misfire. If those are the codes coming up then you would only require 2 coils.... Did he test the resistance of the coils vs OEM specs? Never hurts to test the coils before replacing them.


What was the mechanic saying is making the cat go bad? Too much gas?

 

How many miles on your car? Have you replaced the main relay?

 

Replace your coilpacks, had a very similar problem, this fixed it.

 

Yea I fixed the main relay it was one of the first things I changed, there are approx 145k on it and the mechanic said it was the coils making the cat go bad, but I really believe I have that code because its a aftermarket cat and it will throw that code up because of it

 

What code are you getting for the cat?

An aftermarket cat should still work unless it is one of those test pipes that doesn't contain any catalyst.

Firing a little bit of unburnt fuel down the exhaust from those two misfiring cylinders wouldn't normally kill a cat in that short of a time. In saying that, if it is larger amounts of fuel mixed with oil or other additives it could shorten the life of the catalyst.