So after doing some other maintenance on my gfs 03 CL-S we decided to replace the spark plugs. This was roughly 10,000 miles ago and never got a CEL, the car ran great afterwards. Fast-forward to today and she's been getting CEL for misfires continuously for the last two months, I tried clearing them at first hoping that they were coincidental.

When I replaced the plugs I made sure to gap them via FSM specs and used NGK iridiums. The strange thing with the CELs is that when the misfire is detected it is usually for either 5/6 or 6/6 cylinders. The car has 82,000 miles and still has the original coils. Replacing the coils is likely my next step however I am puzzled why all of them would go bad and with only 82,000 miles.

Has this happened to anyone else? Do these engines have any other ignition related parts that could be the problem? Could this be fuel related? Thanks.

 

I too have a miss fire problem (02 CL) although mine is a little different than yours. After reading several other posts about miss fires it appears as though if any cyl missfires codes may be generarated for any other cyl.

I replaced the EGR and coil packs without success. I guess plugs are next and with 123,000 miles its time to replace them anyway.

I'll be watching both our posts to see what someone suggests.

 

So one bad coil can cause multiple cylinder misfire codes?
That is really strange. I wonder if this was done intentionally so if one coil went you were forced to buy all 6 and spend significantly more money. I plan on changing them all sometime next month, I just don't have to time to do it now.
I'll post back up here when I'm done.

Is there anyway to clear to CEL without the use of a code reader? My maxima has a way (not unplugging the negative battery terminal) to reset ecu, I figured I would at least ask.

 

So I replaced all six coils yesterday with genuine OEM acura coils. While I was at it, I pulled the plugs to see if they were visibly damaged and noticed they were not the OEM plug part number. I bought new NGK laser iridiums IZFR6K11, the OEM plugs, gapped and replaced them.

I cleared the codes using a scan tool at advance auto and not 10 mins later the CEL came back on. So now I'm not only puzzled but really pissed that the problem hasn't been fixed. I called to dealer and they said the ECM could be the culprit or a wiring issue. The service adviser said that ECM's going bad in FL were not uncommon due the the extreme heat (news to me). New ECMs are also $1k.

If anyone on here had their ECM go, please post here or if you have any ideas for me to fix this problem, much appreciated.

I forgot to mention that I cleared the ECM memory by pulling the #13 fuse on the passenger side fuse back per the service manual and did the idle learn procedure. Then the CEL reappeared.

 

whats up, i was reading your post and what i have discovered with my 03cls 6mt is that when i first got the car about 6 months ago, i had misfires in 5 out of the 6 cyl. -- luckly i work for a dealer and was able to find the problem right away. it turned out to be bad/bent valves from the car being over-reved. i then took the two v tec heads off and sent them to the machine shop, port and polished the head and put high preformance valves, also changes the water pump, ngk iridum plugs, and timing belt. put the engine back together could not be more satisfied with the preformance, try that and see if it works! good luck.

 

Do a compression test before you do anything else and that includes driving it. The compression test will tell you which cylinder to look at. If your compression is good then run some seafoam through it.