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It's been a beautiful vehicle. Has about 195k on it. Never had any issues with the car, aside from a power steering pump replacement. Plenty of power, very reliable, and 32-33mpg on trips, 26-27mpg daily driving.
The check engine light has been on for a million miles. Some emissions issue. Never concerned me really. Plus, my state doesn't do inspections of any sort.
A few days ago, I started it in the snow and cold to warm up. I allowed it about 10-15 minutes to thaw out. And then went probing the roads for a safe route to my girlfriends. (The roads were horrible, 4" of untreated or plowed snow on the roads, and 10" on the ground).
Suddenly, I felt the engine become unstable. A little loss of power. Obvious misses. Rough idle.
I turned to go back to the house (I was 3/4 mile away when it occured), and my CEL started flashing nonstop.
I limped it home and parked it.
Now that's it's thawed out and warmed up a couple of days later. I hooked it up to my Walmart special OBD2.
8 codes. 4 of them, which are repeated.
P300 random misfires on all cylinders.
P301 #1 cylinder
p304 #4
P306 #6.
When it comes new Honda's or basically any newer vehicle, I'm sorta at a loss. I mean I can find my way around the basics. Coils. Plugs. Throttle bodies. Sensors. Vacuum lines. Injectors... The visible and obvious things. But internally, or electrically, I'm essentially in mechanical kindergarten.😟
I searched the forums for the p300 code and found several helpful examples. But none really sounded like mine.
I initially thought it was a blown head gasket, because I can smell a bit of antifreeze when it's running from the drivers seat. But when I saw the codes, and realized the misfires are coming from opposite banks (1 vs 4/6) and opposite ends of the same bank. (4/6)
The instantaneous nature of this trouble, has me dumbfounded.
Searches show that plugs are the most common issue. Followed by coils. But the plugs are descent quality nkg, and less than 40k on them. And the fact that I have random misfires through, and especially in 1/4/6... Makes me think it's something else.
Please, if I sound like an idiot before most of you experts -- it's likely because I am. At least on this subject.
So forgive me..
Any help will be greatly appreciated. This is my only car. And I need it running as soon as possible.
Has the problem gone away now that temps have increased?
Instant multiple misfires on several cylinders on different banks are not likely the coils or the spark plugs, so please avoid throwing parts at the problem before doing some diagnostics.
Was any work done recently on the car? Any chance that you filled up the car with gas right before this happened?
Can your scanner read any live data from the car? I'd look at the MAF, MAP, IAT, short and long term fuel trim on banks 1 and 2, coolant/engine temperature for a first pass as these items can affect multiple cylinders. You would want the car warmed to operating temperature and post back the numbers for each at idle then at 2000 rpm. The numbers will jump around a bit, but approximate numbers will work, like MAF ~4.2 g/s, etc.
You may also want to search on your scanner to see if it can read misfires on each cylinder. If only one cylinder has a lot of misfires, then you can troubleshoot coil, spark plug, and fuel injector.
Has the problem gone away now that temps have increased?
Instant multiple misfires on several cylinders on different banks are not likely the coils or the spark plugs, so please avoid throwing parts at the problem before doing some diagnostics.
Was any work done recently on the car? Any chance that you filled up the car with gas right before this happened?
Can your scanner read any live data from the car? I'd look at the MAF, MAP, IAT, short and long term fuel trim on banks 1 and 2, coolant/engine temperature for a first pass as these items can affect multiple cylinders. You would want the car warmed to operating temperature and post back the numbers for each at idle then at 2000 rpm. The numbers will jump around a bit, but approximate numbers will work, like MAF ~4.2 g/s, etc.
You may also want to search on your scanner to see if it can read misfires on each cylinder. If only one cylinder has a lot of misfires, then you can troubleshoot coil, spark plug, and fuel injector.
I have a cheap scanner. Hyper Tough ht309 -- No live data. But i was able to get freeze frame data at about 2000rpm if that helps? (Forgive me if freeze frame is the same thing as live data. I really don't know the difference) Here's what I have. Hopefully it can be interpreted by you or someone...
After clearing the codes... It threw the same codes once more about 2 minutes later. P300, 301, 304, and 306.
To answer your questions... No work has been done on it recently. As far as gas goes, after it started sputtering.. I added 2 gallons of 89 ethanol free gas. Nothing changed. It's probably got 3-4 gallons of fuel in it. And I didn't put gas in it recently prior to it going haywire. Also, it did not get any better with warmer temps.
Thank you my friend for taking time out of your life just to help me. It's overwhelming when a complete stranger dies such a thing.
I'm a disabled army veteran, and don't have too much money to fix this. I'm hoping I can get by on less than $500. But I'm not too hopeful.
First, thank you for your service. I got a lot of help on from this forum when I was broke and was looking at potential expensive repairs, so I enjoy returning the favor.
Freeze frame data are the values stored by the PCM when the code sets, so that information is helpful. Did the scanner record freeze frame data for the P304, P300, and P306 codes as well? Nothing really sticks out in the data except maybe the throttle position sensor % open seems high to me on the second set of data. Since noting in the freeze frame data is obvious, I suggest troubleshooting systematically.
The easiest test is to clear the code with your scanner while the engine is running and recheck the code. You may only get one code return for the problematic cylinder. I had this happen on my TSX (a 4-cyl accord essentially), where the code intially set with multiple misfires, then only returned one code for the culprit cylinder.
I'd next mark each coil top with a piece of tape and marker, paint pen, or whiteout to the original cylinder. On the V6 looking from the front bumper, the passenger side cylinder nearest the windshield is #1. Then 2 and 3 are on the windshield side. The bumper side is 4 5 6 from passenger side to driver's side. I'd swap coil 1 with coil 2 and see what codes you get. Then swap 4 with 5, repeat. Then finally 6 with 5. This can eliminate or confirm a bad coil.
I'd clean the throttle body as a stuck throttle plate might cause these issues. See videos below. I'd remove the snorkel like in the second video, but leave the TB attached and clean the TB like in the first video. A ridge of gunk around the plate and higes can buildup over time and not let the plate close properly to 100% closed. Just use a rag with brake or throttle body cleaner and get the TB bore, both sides of the TB plate, and where the TB plate hinges at 3 and 9 o'clock. The second video shows removing the TB, but you risk tearing the TB gasket and having to scrape off the old gasket and replacing. Check the air filter while you are in there.
I started checking coils by swapping coils and resetting codes, to see if the misfires followed the coil... And then found this one the number #1 cylinder..
--
I'm assuming this was the issue?
Regardless, I have another problem.. all do I get the missing pieces that are seized onto the plug down in the hole? It's on the back side, passenger. I can't get anything in it to grasp on to it and pull it up. And it's blocking my plug socket, and will also block a replacement coil.
That is definitely one issue and hopefully the only issue.
That looks like a nightmare to remove. I'll guess the rubber boot is frozen to the spark plug and the corrosion weakened the glue holding on the plastic bullet shaped piece that remains in the spark plug tube. You'll have to get creative to get out the remaining piece.
I watched some youtube videos to get ideas about removing a broken coil pack in a honda to get some ideas and suggest you do the same.
I think you'll need to spray some brake cleaner or WD 40 and let it soak to weaken the bonded rubber. Brake clean evaporates and makes my next suggestion possible. I'll just list some thoughts on how to remove as there is no simple solution.
My first instict is to remove the rubber boot from that broken coil pack, then see if you force/wedge the coil pack into the broken part to spin it free. Maybe you could miracously pull out the broken piece. If you had brake cleaner or something that evaporates you have a better shot with this method vs wd-40.
My second instict is to find a pipe with tapered threads that can thread into the inside would be ideal. Then you would force the pipe to thread and hopefully grip and break the remaing parts free. Not sure if you have anything like this or should buy something like this, but with the odds and ends around my garage, I take a stainless steel pice of tubing and use a die to cut threads into it as my first attempt.
Maybe find the largest 12-point socket that can fit into that hole and maybe get enough grip to break this free?
I saw some people used some long picks to hook into the rubber from the inside of the remaing piece. One guy used a coat hanger and made a hook at the end to slide it past the outside and twisted the hook to onto the rubber boot and pull up the the stuck piece.
I'd avoid trying to break that stuck part into pieces unless that is your last resort.
After you figure out removal of the broken part... When you go to reinstall the coil, take a q-tip and put a thin coat of di-electric grease on the inside of the rubber boot to prevent this from happening again. You can also put a thin coat on the porcelain part of the spark plug. You want to avoid putting di-electric grease on the metal of the coil or the metal top of the spark plug as di-electric grease is an insulator.
2004, 3.0 auto. Need help. P300, 01, 04, and 06.
