Got a 2000 V6 EX with the distributorless ignition system. It was driving a little rough yesterday. Today, I went to start it and it has a rough idle. Stepped on the gas and restarted the car, still has a rough idle. Started for a third time and the check engine light started to flash. Checked the codes and the following came up:

P0302 01/05
P0303 02/05
P0304 03/05
P0300 04/05
P1399 PD 05/05

The plugs were replaced about 2 months ago. The coils are the original. What else do I need to check.

 

Is that last code a P0339?

 

oops, mistyped the code. It's P0303 02/05.

Not sure if this is related. But I can smell gas fumes inside the car and in the hood. There's no leaks, just smells like exhaust. It tends to go away after the car is warm, but its noticeable on start/warm-up. Is my EGR and PCV valve the culprit to this and the error codes.

 

Update and a bump.

I replaced the plugs with some NGK Iridiiums (old plugs seemed fine still) and checked the coils...all coils seem fine. Also replaced the PCV valve and finally got around to replacing the throttle body gasket. Also added a whole bottle of Sea Foam to a full tank of gas.

Car started up fine, but the sluggishness at idle was still there. Turned off the car and reset the ECU to clear the codes. Started up again and this time let it idle for nearly 10 minutes in order to get the Sea Foam flowing and to check if the CEL would come back on. Within minutes the CEL was flashing again. But when I revved the motor, the CEL would turn off. The idle also seemed to get smoother, maybe because the Sea Foam was working through.

Turned off the car and checked the codes again. This time it only had the following codes: P1399, P0302, P0300 and P0394. Cleared the codes one more time and let it idle again. After 10 minutes, the idle again was smoother, but the CEL was flashing again. Turned off the motor one more time and checked the codes, this time it only had P1399 Code.

Decided to take it around the block. Car seemed to drive fine, it wasn't bogging and it seemed to have power, but the CEL would flash intermittently, seemed to flash at lower RPM's. By the time I came back home, about 3/4 mile trip, the CEL was no longer on or flashing, but the exhaust was smelly. It wasn't a gas smell, it was a little metallic smelling and it wasn't coming from the motor. I assume it was from the Catalytic Converter. Even though the CEL wasn't on, I checked the codes again and it only reads a P1399.

Any ideas on whats going on. Could it be the CAT?

 

You would get a different code for the catalytic converter.

A quick google search of P0394 pulls up this:

P0394 Camshaft Position Sensor "B" Circuit Intermittent (Bank 2). Not sure which camshaft that is monitoring, as I am not familiar with the V6 accord. I am sure there are resistance checks on the sensor, but I don't know the range.

 

I really need to stop typing in the dark as I'm getting to many typos.

Sorry, the error code was not P0394, but P0304. Getting all the same error codes again and the car smells really bad once its warm. Not sure if the misfires are causing the CAT to become smelly. But the smell is quite noticeable outside the car in the midsection.

 

RS250 Chester, did you ever figure out what was causing your CEL and misfire problem?

My 2000 Honda Accord EX V6 is showing the EXACT same symptoms that you described. Been going on for about a year, and the MPG is getting worse and worse. I've taken it in to a couple of garages, had the EGR valve replaced, all spark plugs replaced, and the problem still exists.

Any information you can provide would be much appreciated.

 

Yeah, turned out to be one bad coil. Once it was replaced. All was good.

 

Had the same problem with my 2000 Accord EX V6 Coupe. I bought a scan tool and tried all the recommended fixes, EGR cleanout, EGR valve and fuel pressure regulator replaced, new plugs, checked the valve adjustment and compression. I didn't consider the coils since it was misfiring on all cylinders, but then I found this thread so I thought I would try replacing the coils with a new one one at a time. When I got to the number 4 cylinder and replaced the coil the problem went away, did a road test and the car ran great, cleared the codes and all is well. Thanks to all who post.