2003 Honda Accord

My Honda sounds and feel like it is missing. It has been doing fine and then all of a sudden pulling off from the bank the engine light came on and it started missing. I drove it a block to a service station and park it. We have put in new plugs but the problem is still there. Do you have any suggestions? Some one told us we might have water in the gas. They said we could have purchase some bad gas.

Please report the exact error codes that were read from the computer. The format is “P0123.”

I’d imagine that at least one or more were misfire codes (“P03xx”), so for starters if your shop went straight from spark plugs to “bad gas” that’s a bad sign. But if you report any and all codes that came out it would help in getting started.

Note that if you don’t know what the codes are many auto parts stores read them for free.

The codes are P0301, P0306, P0300, P0303, P0302, P0305, P0304, Thank You. Will be waiting for your response.


Yeah, you’re missing on all 6 cylinders

Did this occur right after getting fuel?

Did you get fuel at a new filling station?

I will never tell anyone that new spark plugs are a bad idea. But I have to say that having all 6 get bad all at once is fairly implausible. (It does sound like this came on somewhat suddenly). This is also true for the control side - each plug has it’s own ignition coil controlled by the computer. I suppose there may be reasons that whole ignition control side could go at once, but given those codes that’s also not what I would suspect.

Had you gotten gas soon before this happened?

Did the shop that you went to check the fuel pressure? This must be done.

How many miles are on the car? Was the timing belt changed on schedule? (I don’t know what the schedule is for this car, but hopefully you’re not on the original 12 yr old belt). Losing a few teeth from the belt will create havoc.


Was the tank low on fuel when this started happening?

Yes I did I bought it at a shell station in Trussville. Al. It did not start until 3 days later, but I drove it very little after buying the gas, Maybe a little over 100 miles

Timing belt was change at 95,000 miles It has approx. 122.000 miles on it now. It was service at Townsend Honda.

I had Half tank of gas, I think when this started

If you did get gas that was that bad, it would have shown up long before 200 miles. It’s not as if it takes a while for the new gas to make it to the injectors. Your existing gas and new gas are all mixed together before you finish pumping.

I’m not ruling out “bad gas” - but I’m really doubting it. For reasons mentioned above, I’d be looking at the fuel system, though - and a little worried about the timing belt. At some point, if the timing belt jumped, you’d get codes reflecting that. But the computers often take a “wait and see” approach before coding.

Do you think we should have the car check again for new codes. I am needing to buy gas now. Do you think a can of
gas treatment would help?

My check engine light will go off and then come back on and sometimes when I get up to about 45 mph the light will start flashing…then it will stop and just say on and then sometimes it will go out. It acts like it is a random type miss. When I first start the engine it runs smooth until I put it in gear and start off after about 4 or 5 minutes it will come on and sometimes flash and them just stay on. Really strange. Thank you


A flashing check engine light means the misfire is severe enough to damage your catalytic converter

You should bring the car to a shop immediately, before you potentially ruin the catalytic converter

Have it professionally diagnosed and repaired

I recommend that you NOT bring it to a big name, franchised shop

Also don’t bring it to AAMCO or Midas. They will try to sell you a rebuilt transmission or exhaust system, whether you need it or not

Thank you for the additional information, and please keep us updated

I took the car and had it put on machine, It was the 6th spark plug not firing right. The mechanic installed a coral pack and it fixed the car. He said with the 6th plug not firing right made it look like all were misfiring. Thanks for the help

That would be a “coil pack”.
Anyway, I’m glad it’s fixed. And congratulations on finding a mechanic that does diagnosis rather than just changing parts. Stick with him.

For future reference, “bad gas” or “water in the gas” is blamed about a million times more often than it actually happens. It happens, but it’s actually very, very rare.

Thanks for all your help

Thanks for the feedback @henri . It’s good to know that one cylinder badly misfiring (probably no spark at all due to a faulty coil pack) can produce DTC’s saying all cylinders are misfiring. It’s sort of surprising the ECM’s misfire diagnostic software is annoyingly non-specific as to the cause, but if that’s the best the manufacturer can do, such a thing is important to know.


It’s not so simple as that . . .

While there may only be a P0300 random misfire code generated, a look at the live data often reveals which specific cylinders are misfiring, and which specific cylinder has had the most msifires

A little sleuthing can reveal a lot. A lot also depends on the scanner being used, and its capabilities

A P0300 can be generated even if it is the same cylinder misfiring. ie #6 misfiring randomly, like once every 5 or 6 or 10 or 15 power strokes. If it misfired every power stroke then there would be a good chance it would be a P0306. At least i think so.

I drove a 2012 Honda exl v6 It drove well until I apply the brake and just before it stop it had a slight shimmy in the very front of car. It only happen when i apply the brake and just before stopping it shimmy some. Do you know WHAT this could be? It seems I can not get away from a car that does not vibrate, shake or shimmy lol.