Hey! I'm looking to get some help with an issue I'm having. I have a 2000 Honda Accord LX V6 with 168k miles and it is rough (vibration) in park, when stopping until brakes are pushed, and between 50-55mph but runs much smoother at highway speed. MY CEL is on and I pulled the engine codes P1399, P0301, P0302, P0303, P0305, P0306 and P1259 indicating cylinder misfires and VTEC malfunction. I have read through multiple threads with some finding solutions by replacing spark plugs, cleaning/replacing IACV, cleaning EGR valve and passageway. I was going to start by cleaning the IACV and EGR passageway. Has anyone had these combinations of codes before and know which steps should be taken? Please help. Broke med student here

 

A flashing CEL while driving is a bad thing.

If the plugs are due, they are wear items and should be replaced when due.

My guess as to where to start testing. Since the '00 V6's are COP, I'd check to see if you have a bad coil. Since you have a bit of "vibration" at idle, unplug each of the coils one at a time. Unplug one, see if the idle/vibration gets worse. If it does not, plug that one back in and move to the next one.

I'm willing to bet, a cup of coffee, that at some point you will unplug one coil and the idle/vibration will not change....bingo. To be sure you can switch the coil froma cyl that "DID" change the vibration with the one that did not and re-test.

Again, if the "no change" follows the coil, pretty sure bet that coil has gone bad and needs to be replaced.

Highly suggest taking care of the flashing/mis-fire codes first. They can lead to damge of other things pretty quickly.

For the 1259. The first thing to do is check the oil level. If low, top it off....unless you are close to an oil change, in that case I would go ahead and do the oil change.

PLEASE start with the mis-fire codes.

 

So I did as you stated and you were right on! I guess I owe you a cup of coffee! I took off the sensors and got no change for one of my coils then swapped it and the swapped coil was still bad. I just went ahead and ordered a coil and 6 new spark plugs since I don't know when they were changed as I bought the car used a couple months back. I greatly appreciate your help and I'll update in a week once I get the coil to let you know how it goes.

 

It is early and I'm still getting my coffee intake

I'm a bit confused on part of your comment. If the coil is bad it will follow no matter where you move it.

So if cyl #1 if having an issue - you pull the coil connector and no change to idle. You then put another coil on cyl #1 and do the same test and get the same "no change" to the idle.......you either have another bad coil or there is something else wrong with cyl #1.

 

The only miss fire code you did not have was cylinder 4. Clear the codes, swap cylinder 4 coil with cylinder 1. If miss fire code for cylinder 1 goes away and cylinder 4 shows up then that was a bad coil. If cylinder 1 code reappears and cylinder 4 does not appear then we are heading down a different road...

 

Sorry about the confusion. What I was saying was that when I swapped the coil the problem followed the coil indicating a coil problem and not something else with the cylinder. I then pulled the bad coil to inspect and it was cracked.

 

I got it now.....yes I'm slow sometimes.

Yep, a new coil and things should work out better.

Once that is done, re-set the codes and if the 1259 comes back let us know and we'll see what we can come up with on that one.