Random Rough Idle

[s6skuzy]

Have a 2004 EXL with about 36K miles. Experiencing a random rough idle or a miss when at a stop light. Seems to run fine then every now and then, I feel a miss. No error codes are being thrown. Experienced a similar problem when it would run rough at 33K miles, but took it in and dealer said it was a bad plug. Threw an error code that time. Did a search and didn't find anything similar. Any ideas?

Thanks

[humanoid]

Have you done a search for "EGR valve"? It sounds like you may have a bad one.

[cwa107]

Originally Posted by humanoid

Have you done a search for "EGR valve"? It sounds like you may have a bad one.

That was my thought as well. Very common problem I've seen here a time or two.

[s6skuzy]

Thanks...

I did search for that, but it isnt throwing an error code. It appeared that most had an error code thrown. Unless, this is just the start of it and will throw one soon...

[s6skuzy]

Used some fuel injector cleaner (gas additive) and it cleared up the problem for about a month. Filled up with Sams gas and its back again. This time the MIL and VM light is on. Took it to AdvancedAuto and its throwing codes P0305 (Misfire on 5), P0306 (Misfire on 6), P0300 (Random multiple misfires), and P1399 (Manufacturer Ignition System Code).

Taking it to the repair shop tomorrow. Any ideas/guesses?

Thanks

[OhioBobcat2000]

No chance you're getting misfires from bad plugs this early, unless you're using leaded gas or running diesel in it. I'd go with a computer/emissions valve issue to start. Take the codes to the dealer and see what they say. Then, if you don't like their answer, find the best indy mechanic in Detroit and go there for diagnosis.

[s6skuzy]

Inspected the ports and it wasnt bad. Some carbon around two ports, but nothing close to being clogged. Cleaned it up and put it back together. Still same rough idle.

[s6skuzy]

Had it in the Dealer for a similar issue back last fall and they diagnosed it as a bad plug on number 2. Was under extended warranty at the time but they wouldnt cover it stating its a wear out item. Cost $140 if I recall to repalce one plug and to be diagnosed. Only has 37K miles on it now, but agree its a tad early for plugs.

[cwa107]

The EGR valve is a fairly common failure in the early Pilots and can definitely cause misfires.

Have a look at this thread:

check engine light-need advice!!

...and this one...

Engine Light: Misfire...help!

If you Google those codes in conjunction with the words "Honda Pilot", you'll see the same thing turn up time and time again.

[s6skuzy]

Tempted to replace the ERG, but looks like there about $100 at AdvancedAuto. Hate to replace it with no error codes indicating there is an issue with it.

[rocky]

Surely its not the gas......I'm amazed at a 04 pilot with so few miles....

[s6skuzy]

Well, its possible its the gas this time around... Could be getting some bad gas from Sams every now and then. Tried to call them to see if there were any other complaints, but they were closed already.

[cwa107]

You might want to try cleaning it first:

How to Clean an EGR Valve in a Honda | eHow.com

[OhioBobcat2000]

Eh....bad gas from a warehouse club seems unlikely. While I used to be a gas snob, I now realized (and researched) that as long as it's a large, well-maintained, quick turnover station, bad gas shouldn't exist. I buy gas from Costco once a month and can't complain.
However, you may be correct. I still say unlikely.

[samelcamel]

You probably shouldn't be troubleshooting something that's a "consumable" like spark plugs. If it were myself, I'd buy new plugs and replace them. Just because you can run the plugs for 100k miles, doesn't necessarily mean you should. Also, it should eliminate that as a potential cause and it couldn't do anything but help your cause.

Good luck!

-Sam