hey guys, I have a 2002 Honda accord SE. I recently had my CEL come on and it blinks.
at a stop light it idles a little rough but driving is completely fine.
I did new cap, rotor, plugs and wires. I used NGKs.
I had my car scanned at autozone and got the following codes; P0302 (Cyl 2 mis), P0301 (cyl 1 mis), P0300 (multiple misfires detected) and P1399 misfire in any cyl.
I am getting aggravated why I cant figure this out

 

anyone?

 

What is the mileage on it?

You might want to do a compression test. Do you know if the valves have been adjusted.

 

x2 Check compression on the engine and valve adjustment. Should also test your ignition coil and ignitor inside the distributor while you're at it. If they are week, the engine may still fire but the spark may not be strong enough at higher RPMs.

Misfire conditions can be cause by a number of things. The main areas to look at are, cylinder compression, clean, proper volume of air, strong spark and proper fueling. If all of these components aren't right, the engine can misfire.

I realize that you just put new spark plugs in, that makes this little test even better. Remove all 4 spark plugs and check their condition.
White and chalky = lean fuel condition - Low fuel pressure, dirty injector(s)
Black and sooty = rich fuel condition - week spark, improper fueling (dirty O2 sensor/ECU issue)
Black and wet (smells of fuel) = extremely rich fuel condition - No spark, poor compression, leaking fuel injector

Next two aren't always associated with the basic DTC misfire codes. However, if you have smoke out the tailpipe, one of these could be the issue.
Clean and really shiny = Coolant/water in combustion chamber - leaking head gasket, cracked head or block (usually accompanied by white smoke out of the tailpipe)
Black and wet (smells of oil) = worn valve seals, worn or broken piston rings. (usually accompanied by grey/blue smoke out of the tailpipe)

 

I have about 153xxx. I am the second owner of the car and purchased it at about about 132k.

I will have to get the tool to check compression. And I don't think the valves have been adjusted.

 

I cannot thank you enough for this information and reply. I am not familiar with misfires at all. You now have me understanding exactly how a misfire happens.
I will start with checking the plugs.
If I do remember. Correctly I believe the old plugs had some white debris on them. However, when I replaced the plugs and all that I had purchased some Lucas fuel injector cleaner and I must say it's been running a lot more smooth but the CEL is still on, for surely actually hasn't blinked since yesterday.

 

If you get the flashing CEL while driving, that is the indication that the misfire is happening at that moment. If you do see that again, try and remember what speed and RPM you were at. I know it's a lot to try and remember when you're not used to vehicle diagnosis. But it may help us help you.

Where this is a 2002, if you have a friend with a hand held scan tool, you should be able to get the freeze frame data from the on-board diagnostics (OBD). This is a capture of what the sensors were seeing at the time of the error condition. This information can also help in diagnosing the misfire. Not sure if Autozone will give that to you or not? They may just have a basic code reader that only gives you the P code(s) and that's it.

 

I suggest watching some Youtube videos from people like Scotty Kilmer, EricthecarGuy and ChrisFix about diagnosing misfires. You can buy a wireless bluetooth device, the BlueDriver by Lemur Technologies, for about $100 and it works with your smartphone and it has the Freeze Frame, code reading, and live data functionality. I have one and I used it to troubleshoot a very similar misfire on my daughters 2000 accord SE, 4 cylinder. I was getting P0301, P0302, P0300 and P1399 as well. . On mine, I tried replacing the distributor cap, and coil, but it turned out to be the fuel injectors were clogged. I went to a junkyard and uninstalled injectors from what appeared to be a well cared for engine on one of these cars (There are lots of these cars, built from 1998-2002 model years at junkyards). and they worked just fine for $8 apiece, (and they came with a 30 day warranty!). New ones are over $100 each from Honda so it was worth trying. If you want to try the injectors at some point, just reply and I can give you more details on how to check the ones you have (resistance, signal), and how to uninstall and install the "new to you" ones.

 

I didn't know when it is blinking that's the actual time it's misfiring. Valuable info. It was happening around 3k rpm. I am under the impression that the fuel injectors were clogged. Ever since I ran the Lucas the blinking light has stopped and stayed solid and the car ran so smooth again. I ran the car for a while seeing if it would rest itself as some code do. Which it didn't. Before taking a decent trip to the boardwalk I pulled my fuse to reset the light and hasn't came on since. So as I fill up I'm going to run some of that Lucas for about a month and a little bit of super. I am going to get the Bluetooth scanner tool for smartphones for further complications.
thabk you so much for the info. Breaking down what can cause a misfire has helped me plenty. familiar with cars just not these issues.

 

the people you mentioned on YouTube are AMAZING. ericthecarguy is great. We had the similar problem. I have a 02 se and I replaced all the tune up stuff and was baffled it was still misfiring. I am going to take your advice and pick up some new injectors from the yard soon.
But as of now after running the Lucas my car feels brand new again. No issues as of yesterday resetting my CEL. Definitely getting the Bluetooth scanner

 

Also would the Bluetooth read a OBD I? I'm building a b20 dropping it into a eg soon and that scanner would actually help if I have any problems.

 

The BlueDriver will not read OBD1. Very few scanners will. Not sure how to advise you on that one but probably your local auto parts store can tell you what options they have, or you can look on Ebay or Craigslist.

Separately, if you want to really learn how to diagnose car problems, so that you only replace/fix the part that is broken, the very best source on YouTube in my opinion is Schrodinger's Box.

 

thank you man. Ima look into that. I appreciate all the help from you & the others

 

multiple misfire codes tend to be a crank sensor gone bad

 

K-G when was the last time the valves were adjusted?
Intake side is probably still fine, exhaust valves are usually the ones that sink and lose clearance. When cold the engine will be fine but as it warms up and tolerances get tighter the exhaust will not fully seat/seal and you will have loss of compression and a misfire. Problem with this is that by the time you have a compression/leakdown gauge attached, the engine has cooled down enough and the valve will not be hanging open.
If you haven't, check and adjust the valves.

 

Was not sure if I should bring this back from dead but why not?

So, here goes 2000 accord ex ULEV f23a4



Symptoms: excessive oil burn @ 234 miles a quart on diesel oil 15w-40 (was burning more at regular oil 5w-30, 156 miles a quart)

Misfire started recently, first symptom was low rpm, quick rev would fix the issue. THen it got bad and stalled, next came the misfire all cylinders. P0300, P0301, P0303, P0304 and P1381 CYP SENSOR INTERMITTENT INTERRUPTION

pull the plug wires one by one. Cylinder 1-3 gave me feedback such as shuddering. Now cylinder 4 exhibited no change, and this is the cylinder that is fouled with black oil


The service manual I'm using says nothing of the location of the cyp sensor, i'm going to double check. but could it be near the crank pulley