Flashing CEL, TCS Indicator, Misfire Codes

[soxfan50]

To start, I have a 2002 Accord EX V6, approx. 68,000 miles.

I was idling in a drive-thru the other day when I noticed some sputtering of the engine. Pulled off to the side, turned the vehicle off, turned it back on, and upon backing out of the parking space, my CEL (which has been on for a P1457 EVAP code for awhile, which I just have not gotten around to fixing) began blinking. I was only about a mile from home, so went straight there - on the way, the TCS indicator turned on.

The only driving I've done since was to head to AutoZone for a code read (apprx. 3 miles round-trip). Codes read as follows (aside from the P1457):

P0300 - Random misfire
P0303 - Cyl. 3 misfire
P0306 - Cyl. 6 misfire
P1399 - Random misfire

I've been browsing around the forum (and elsewhere) for where to begin on this. I have not had any work of any kind done as of late. I tried the ignition coil pack test (unplug individually while in idle) and it seemed the 2 and 3 (not 3 and 6) were the only ones that didn't seem to alter how the engine idled.

I guess my questions are: (1) what is the significance of the TCS coming on in conjunction with the above CEL codes? (2) generally speaking, what's the difference between the P0300 and P1399 codes? and (3) what is the suggested beginning approach for this? Seems like switching out the spark plugs and/or ignition packs would be easy enough, and seem to be a suggested course of action for many similar situations, but I'm not entirely sure.

Thanks in advance for any help.

 

[xci.ed6]

For starters...

Autozone won't clear your codes, so get your own reader.

Swap 3 & 6 with 1 & 5, coil packs & plugs.

Note plug condition & type when removed.

Clear codes, drive until the light comes back.

What are your codes now?

We are doing this to find out what it is. It would be very rare for both plugs to die at once, and COP?!?! That'd be nuts! I honestly doubt that it is, but we always gotta start somewhere.

 

[james'99]

xci basically said it. TCS was on due to misfire so that is normal. CEL flashes when damage to catalytic converter is going on so that explains that. You can also check your egr passages. Other than that, one of the backup fuses should clear your codes if you pull it out momentarily. The one on the pass side in door fuse box I think.

 

[soxfan50]

I'll try the switch today and see what happens. The vehicle has had a slightly rough idle for awhile, but it was noticeably worse in the minutes before the CEL began flashing. Also notice a strong smell of raw fuel.

One question:

We are doing this to find out what it is. It would be very rare for both plugs to die at once, and COP?!?! That'd be nuts! I honestly doubt that it is, but we always gotta start somewhere.

What's COP?

Will report back once I've performed the switch.

 

[xci.ed6]

Oh, C-oil O-n P-lug

 

[xci.ed6]

Changed my mind a bit:

COP swap with 1 & 5
Plugs swap with 2 & 4

 

[soxfan50]

Thanks for the information. I'll try that - did not get a chance the last couple days, and wanted to pick up a spark plug socket. Realize that the paper/socket trick is often used, but considering I can get the right tool for a few bucks, figured it would be best to do it right.

Obviously everything depends on the results of this diagnostic work, but would it seem most likely to be a replacement of some combination of spark plugs/coil packs, correct? Just wondering if I should order those online (go through Amazon prime), and if it comes down to it and it's something else, I'll just return. Just a bit antsy to get the car back in driving shape, and if I can get the parts on their way to me, could shave a couple days off that.

Thanks again.

 

[spacemonkee23]

Random misfire, hopefully its not the ECU. If you drive on a misfire for too long then raw fuel is going to melt your cats causing larger $$$ problems. Check your cats if you can.

 

[soxfan50]

Random misfire, hopefully its not the ECU. If you drive on a misfire for too long then raw fuel is going to melt your cats causing larger $$$ problems. Check your cats if you can.

How would I go about doing that? Definitely noticed a raw fuel smell since the time the CEL began flashing, and upon the couple times I started up since (not driven, only to perform an unplug test of the coil packs).

 

[spacemonkee23]

Usually a flashing CEL is misfire. You would physically have to take the catalytic converter off and shine a flashlight to look at them and see if they are melted. Typically it takes prolonged driving with a misfire to do noticeable damage to the cats, so you should be fine. After the fix, if you have lack of power and poor MPG the cats may have melted.

Also watch this...



if that doesn't work try:

Troubleshooting Multiple
Misfire DTCs
NOTE: This article applies to ’98–02 Accord L4s,
’95–02 Accord V6s, ’98–01 Preludes, and ’99–02
Odysseys.
When troubleshooting misfire DTCs (P0301 thru
P0306) with the PGM Tester, look at the freeze
data values for the throttle position (TP) sensor
and the exhaust gas recirculation valve lift sensor
(EGR VLS).
If the EGR VLS value is more than 1.25 volts, and
the TP sensor value is 0.5 volt (closed throttle), the
EGR valve opened when it should have been
closed, and is defective. Replace the EGR valve.
If the TP sensor value is more than 0.5 volt, and
the vehicle speed sensor (VSS) and RPM values
indicate that the DTC was set while the vehicle
was moving, write down or print out the EGR VLS
value. Then, drive the vehicle at the same VSS and
RPM as shown in the freeze data, and note the
EGR VLS value:
• If the freeze data EGR VLS value is more than
1.25 volts, but the EGR VLS value from the test
drive is less than 1.25 volts, the EGR valve was
stuck open, and is defective. Replace the EGR
valve.
• If the EGR VLS value from the test drive is
similar to the EGR VLS value on the freeze
data, the EGR valve is OK and isn’t the cause
of your misfire DTC problem. Look for other
possible causes.