Hi guys,

I have a 99 Honda Accord V6, my CEL was blinking as I was driving on the freeway and the car started to misfire and shakes as I accelerate. I looked up the code at first it was a MISFIRE in every cylinder and P1399 (Random Misfire). I changed cap, rotors, wire, spark plugs , but the problem is still there.

I know the accord has 1 ignition coil that goes into the dizzy, I changed that also but it didnt fix the problem. Car seems to be backfiring when you rev up to 2k RPM. When MAP sensor is disconnected, car drives normal. So i thought it was the map changed that, but same problem came back.

I'm really frustrated and can't think of anything else, would anyone be able to help or experienced the same problem?

 

what kind of coil did you change to? check to see if any wires are loose on the dizzy

 

I changed it with an OEM one. no wires are lose, Just changed cap rotors and wires today as well... didn't fix the problem.

 

Replace EGR VALVE, but first take intake manifold off, clean out EGR Port's (port on intake manifold, and port where EGR mounts) with carb cleaner. Then put new EGR on, then reassemble intake. I would also replace the knock sensor.

 

egr valves are built to last so don't change that until you've exhausted EVERY other option. If anything you can just clean it.

However, pull the egr valve connector and see how the car runs. Obviously this will throw an egr valve code but you just want to isolate the egr circuit. Does it run fine before the car warms up ?