Jjb122

My 03 accord ex v6 started misfiring I check the codes and have p0300-p0306 along with a p0404 I swapped out the egr hoping that would resolve my problems but I wasn't so lucky I was hoping maybe someone can point to me in the right direction along with the misfires I have a rough idle and a hard startup where sometimes I need to pump the gas pedal...and besides that I smell fuel under the hood close to the egr valve injectors seem to be making a rattling noise instead of the steady ticking noise which it normally does but I don't know if that's because of the problem I can't yet find any help would be appreciated

poorman212

One of the coils could be bad causing the misfire code(s). Had to say so some testing would be needed.

Jjb122

Yea I will look into that but there c.o.p so if every cylinder misfired you still think it can be a bad coil I mean it's possible one is bad but everyone

poorman212

Trust me, the PCM can and does get confused when "one" coil goes bad. The PCM will try to adjust for the "knock" and things just go south from there and you will get multiple misfires.

If you have a "bad idle", the simple thing to do is disconnect one coil at a time and see if the idle changes. If it does then "that" coil is good.....reconnect it and move to the next one. At some point you will disconnect a coil and notice the idle did not change, that is the cyl you need to investigate/test.

Now the 0404 could also cause the misfire too early and not enough coffee when I first posted. I see you replaced the valve already, not sure what testing you did to come to the conclusion it was bad? I'll assume the testing showed all of the inputs/outputs from the valve and the PCM are good. You might try cleaning the egr ports, don't see as many 7th gen V6 accords clogging as you do the 6th gen V6 accords but it can't hurt.

Jjb122

I am definetly going to take your advice and take it from there I really appreciate your feedback

Jjb122

Well poorman your advice definetly helped cylinder 6 actually blew the plug out of the head bending the plug and destroyed the coil...and not only that it stripped all the threads in the head so I had to tap new threads...so where I'm at now is I replaced all the plugs and the ruined coil...but the car is still misfiring in cylinder 6...I'm going to pressure test the cylinder even though I think if the plug bent like that and caused that much damage to the coil it had to be getting enough compression to do that...so I was curious to what you may think...faulty injector?...I could do a fuel pressure test but that's not going to tell me if an injectors bad...and it seems on an 03 achord you need to remove the intake manifold to access the injectors which kind of sucks

poorman212

I hate to say it but there is likely damage to the valves in cyl #6. A compression test and/or leak down test will help to figure that part out.

Jjb122

I ran a compression test and it's 15lbs less then a cylinder that isn't misfiring I also ran a fuel pressure test which says I only have 10lbs of fuel pressure...my car doesn't have a Schrader valve so I hooked my tester where it comes into the fuel rail and hooked it so fuel would pass through the tester I'm just questioning that giving me an accurate reading as for compression I think I'm supposed to have 135lbs....cylinder 2 a good cylinder had 130...and cylinder 6 had 110

poorman212

I'm surprised you have compression, if the piston and spark plug "some how" came into contact and pieces start bouncing around inside the cyl.....something bad usually happens. I would still wonder what a leak down test shows on that cyl.

For giggles, did you test the inputs to the coil just to be sure it is getting a signal to "fire"? I'm just trying to rule things out in my head before jumping into other things.

I saw your post about the injector, I passed on answering - sorry. Anyway, at the PCM connector. Pin E4 is "common" to all injectors and pin E27 is the "signal/pulse" to the injector.

I hate to jump/suggest it is an injector but if everything else is checking out....well it would be the next to test/verify. Not fun to pull the intake but it is the way it is designed.....it even has to go to pull the valve cover, which I would pull just to verify the cam/rockers.valve stems are all good for that cyl.

There are a few other, "since you have the intake off" things I would do.....since it is off clean the egr ports in the intake, might as well check/adjust the valve clearance/lash....ect.

Not trying to give you the "run around" just trying to help where/when I can - yes I'm not on here that often so if others have ideas

Jjb122

Yea I completely agree with if I have the intake manifold off anyway...you have really been a huge help...I'm going to run another fuel pressure test to reassure there is an issue there cause like I said the first test I ran only gave me 10psi which is obviously way to low but that may have been the way I had the gauge set up...thanks for info on pcm wiring...all in all you were a big help thank you and merry christmas

poorman212

Let us know how it turns out....or what new findings you come across.

Jjb122

Well I'm pretty much stumped fuel pressure is still at 11psi I changed the pump changed the regulator I did voltage tests /voltage drop test everything is good...fuel pressure is still low...I replaced my egr and now the new one is leaking fumes which is very visible coming from the diaphragm so maybe I got a beat egr I don't know after finally taking care of the misfire and original p0404 when I thought it may have been fixed I got a p0172 and the p0404 came back I'm lost compression tests where good what else can be wrong