So after spending a few hours last night trying to adjust my clutch so the catch point is right and of course not succeeding my check engine light came on on my way to work. A month or so ago I got a P1399 as per everyone's advice I checked the plugs and re-gaped them and problem went away. So when my CEL came on today here's the codes I got:

P0301
P0302
P0304
P1399 --> same code from before

So appears as though I had misfire in three cylinders (1,3 and 4). I was thinking that it would be the coil packs but I replaced the coil in cylinder #4 about 6 months ago. I would prefer to fix the problem myself but I think this one might be over my head. Any ideas?

 

Faulty coilpacks. You're having random misfires. You should have changed all 4 the first time around.

 

I agree, it's probably your coil packs.

 

Yea I was thinking it was the coil packs, anyone know how to test these? I have been doing some searching and it seems as though you can use a multimeter to measure the resistance but I am not sure exactly how to do this. Also should I replace all the spark plugs if I do replace the coils?

 

Well I just decided to look at my plugs and noticed something very strange, the top ground electrode actually cracked off on three of the four plugs!!! How could that happen??? Anyways heres a pic, sorry its from my cell camera the gf borrowed (stole) my camera. The strange thing is that the plug closest to the firewall looks fine, which I would think is cylinder #4. The only cylinder that had no misfire was #2 which I would think is next to #1. I'm confused.

 

Don't take this the wrong way ... Did you gap them properly when you re-gaped them? And have you re-gaped them multiple times?

 

I actually didnt even gap the plugs I just checked em to make sure they were fine. I am 100% sure it was not a result of me checking the gap. I put em in the car about 1 year ago. I guess I will just buy new plugs reset the CEL and see if I still have a problem.

 

What kind of plugs? Brand, model and part # please. When you say the "top" are you talking about the part the coil-pack goes to or the actual tip of the plug?

 

I'm using the stock NGK PFR7G-11S.I'm talking about the actual tip not the end the coil pack goes into. Last night I found some old plugs (same model NGK) lying around that were iin ok condition, so I put em in the car and reset the cel. The CEL has stayed off for my 20 mile commute to work but the car has a very rough idle. It almost stalled at a few times when I was stopped at red lights. I'm going over to a local Honda stealership today and am gonna grab 4 new plugs.

 

Just get the plugs at an auto parts store. No need to pay the honda premium!

 

I called around all the local auto part stores but none of em have the plugs in stock and I need em asap. The dealer has em for 16 a piece which isn't terrible. Advance Auto does have the NGK iridium plugs (IFR7G-11KS, same gap and heat range) in stock for 10 bucks, would I be ok running those over the stock plugs?

 

This is what you need to know... https://honda-tech.com/forums/showpo...61&postcount=8

Post is from this thread.

 

I just stopped by the honda dealership (the only one I like) to pick up new plugs. I ended up talking to one of the senior techs and the only reason he thought of for the spark plugs to break like they did is some sort of foreign object in the engine or possibly a bad pcm. I decided to bite the bullet and pay em 100 bucks to look at the car. We'll see what happens.

 

Now why would you go and do a thing like that? There is nothing he can do that you can't.

 

They impressed me with a little snake camera that they had kinda like a colonoscopy (not like id know) for the engine. So I paid them the $100 and watched them look through the engine, plus they adjusted my clutch free of charge. What did they find was the problem, nothing they saw no problem and recommended that if the CEL comes on again to bring it in and they will look at free of charge. So the car seems fine with the new plugs and my clutch feels better so all in all worth it. Thanks for all the words of wisdom smoke.

 

I had that same problem recently. I bought new fuel injectors and it fixed my problem.

 

Sometimes the ECU will get an odd, random misfire code...usually on startup. When you reset the ECU does the problem go away? This is a common intermittent problem in most Hondas. Your plug electrode should not break off though.

 

When I got the random misfire it was under heavy acceleration not during startup. The random misfire did not make the CEL stay on it just blinked for a second or so. The code was stored and a month later (this week) when I reset the CEL the random misfire is not stored and has not blinked since I changed the plugs.