Check Engine - Code P0301 - Misfire on cylinder 1

[Stuckey]

02 EP3, No Modifications, 86,xxx miles, got the P0301 code. Replaced spark plugs, gapped them and reinstalled them. Reset code, ran for a few weeks, code came back. Removed ignition coil from plug 1 and put it on plug 4 and put 4 on 1 and reset the code to see if the code would follow the coil or not. Couple weeks later code came back on cylinder 1. Ran compression check on all cylinders and got 178 - 1, 180 - 2, 180 - 3 and 180 - 4.

Any advice as to what I should do next? I wouldn't think a 2 psi drop on cylinder one would cause a problem but I"m open to ideas or tests to run to get to the bottom of this. They car seems to be idle rough intermittently.

The valves were adjusted at approximately 60,000 miles. Probably time to adjust again?

[talonXracer]

Clean/Check the injectors, 95% of the time a misfire has nothing to do with ignition, but with fuel/vacuum issues.

[Stuckey]

Clean/Check the injectors, 95% of the time a misfire has nothing to do with ignition, but with fuel/vacuum issues.

Of the last 3 tanks 2 I ran with Seafoam in it and the most recent was Lucas Fuel Injector treatment. Sounds like this may not be enough and will have to have the professionally cleaned and/or replaced?

[talonXracer]

Go for a ride and get that crap out of the tank and fill up with some top tier fuel. I would also have the injectors cleaned/checked.

[smykhaisouk]

you dont recommend lucas fuel treatment at all? i recently used this about 2 days ago and have about half a case of this left. i try to get a bottle in after every oil change.

Goodluck on this stuckey.

[talonXracer]

No, I do not recommend that crap.

You can check to verify that it is that injector by changing the injectors around like you do plugs and coil packs.

[Stuckey]

Go for a ride and get that crap out of the tank and fill up with some top tier fuel. I would also have the injectors cleaned/checked.

Thanks for the info Talon. In lieu of bringing the car into the shop right away, would it be of benefit to run through a couple of tanks of premium (91 octane) fuel from say Chevron and then back to 87 octane and see if the check engine light will come back on, or should I just bite the bullet, pay the shop to clean them at this time?

[japarossa]

I wouldn't put seafoam in a Honda motor or you are just looking for problems, expect another check engine light for the o2 sensor soon.

[T_Virus]

check your valve clearance again...

I had misfires on 1, 3 & 4 and random...I did what you did to as in swap the coils, spark plugs, got my compression test and all became normal...I didn't know what to do anymore and took it into a shop and they found out my valves needed to be adjusted. So they adjust it and reset the check engine light and it fixed this problem...

What is odd is that I didn't know a valve being off spec and cause a misfire...normally it is the coils or spark plugs.