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5 ignition coils failing simultaneously?

I have a 2002 Honda accord. Ive only had it for a few months. I haven’t had any real issues with it. The other day I left for work and stopped for gas. No problem. As soon as I start the car back up, its thumping and my engine light is blinking. Quick Google search tells me its dangerous so I ran to advance auto to get a printout of the codes on my way back home. Turns out I had SEVEN codes. Misfire in cylinders 1, 2, 3, 5, and 6. A mechanic friend of mine walked me through checking my ignition coils. With the engine running, I unplugged one at a time and listened for a change. Nothing happened when I unplugged them, except for one. So FIVE of them went bad? At exactly the same time? And beyond that… I’m at a loss for how this car was still drivable with only one good coil. Didnt even sound bad. The thumping was even minimal.

Ive ordered new ignition coils to replace all 6, but I’m completely at a loss as to how or why they all failed suddenly after getting gas.

i would replace your spark plugs first. If the gap in your spark plug widens due to normal erosion, it leads to an increased voltage being required to create a spark in the chamber. The increased voltage demands more current flow through the primary circuit and this increased current flow can overload the primary transistor. Keeping all these components in good running condition is also a big help towards keeping your coils in a good working condition.

Disabling an ignition coil can give indication if a cylinder is firing or not but does not prove that the coil is the problem. Your analysis is flawed, the engine will not run on one cylinder, you need to perform further diagnoses, perhaps you put the wrong fuel in the car.


I personally think it was bad gas. It happened suddenly, immediately, and definitely not isolated. But EVERYONE ive spoken to, mechanic or otherwise, says its highly unlikely and sounds like either spark plugs or ignition coils. Should I call the gas station to ask if they got any other complaints?

Take a sample of fuel from you car in a clear container and see if it separates (water).

Unfortunately, (and I’m already kicking myself for this) I tried adding high octane gas from a different gas station in hopes that it would help. But the day before pay day… $12 of watered down gas and $10 of premium gas probably didnt matter.

My approach is to start with the basics - Air, Fuel, Spark and yes it is unlikely that 5 of 6 coils fail at precisely the same time.

  1. Air filter clean, no Throttle Body / MAF codes?

  2. Are you getting fuel pressure?

  3. Are the spark plugs clean, gapped correctly and throwing a spark?

Just a WAG but on a car that’s 16 years old I’d check your fuel injectors next. Crud bulidup, corrosion and just plain wear will take it’s toll and then a single “bottom of the tank” (your car’s or the filling stations’ tank) can push them from marginal to kaput.

I replaced all six spark plugs and ignition coils yesterday, so that isn’t the issue. However the spark plugs did look fried. Yes they’re gapped correctly. Right now I’m looking into a vacuum leak, and possibly/probably needing to clean the EGR valve if I ever get the bolts off. I also replaced the air filter yesterday so thats all good. I do get fuel pressure. The engine runs slightly better while driving, although I only took it to the end of my street and back. There’s a clicking noise coming from one of the hoses for airflow I’m not sure what its called I’ll attach a pic. It stops sometimes. Slight hissing noise coming from that area but hard to tell since my engine isn’t as quiet as it normally is. I also just noticed yesterday a gas smell when I start the car but it goes away after a minute. Nothing is leaking onto the driveway though. Hopefully its not the fuel injectors, but I’ll move on to that last. I use Lucas fuel treatment weekly so hopefully thats done me some good.

These are the codes I had on June 5th, not sure if they’ve changed or not. The p0780 has come and go since I got the car I’m not dealing with that one right now. The 7 others all came up at the same time.

So you’re going to spend another $300 on injectors without knowing the cause of the problem?

I don’t know if this is a joke but if it isn’t, please stop throwing money at the problem and take it to a qualified mechanic who has the knowledge, experience and equipment to properly diagnose and repair the problem.

I said fuel injectors were the last thing I was checking
Three different “qualified mechanics” diagnosed wrong.
One wanted to replace ignition coils. I wasnt paying hundreds for that so did it myself cos it needed to be done either way.
Another one wanted to replace a fuel injector relay, I already that was bs and moved on to another mechanic.
Next one swore it was the EGR, which had already been checked and cleaned. Then said it was a vacuum leak, but couldn’t find it and neither could I.
The fourth mechanic a week later figured out my intake manifold needed to be cleaned. And that was all.