I filled up with our new ulsd yesterday, now my truck is idleing like crap and when you step on the throttle it chatters alittlie puffs some smoke (possibly) blue, hard to tell. It doesn't happen at every light. just a few times. It really idles rough when this occurs. Almost wonder if it's going to stall. Bad fuel? Not throwing any codes. Wish it would, that would help. Just changed fuel filter 300 miles ago.

Sounds like some bad fuel. Could be they just got a delivery on a near empty tank and really stirred it up.

Perhaps some water. I would drain off filter and inspect for a water presence.

I've got the same problem. I'm trying a fuel additive thinking that I've got a jammed or otherwise *****ed up injector. Lets see if it helps - it does seems to be getting better but it hasn't gone away completely. Stay tuned.

Well i'm going to the stealer on Friday. Just one more thing for them to check.

Well i'm going to the stealer on Friday. Just one more thing for them to check. Give us a report when/if they figure it out.

If is right, they'll probably say " oh thats normal" or "we couldn't duplicate it"

My dealer (over the phone) told me to make sure the oil level is ok - if it is then ignore it - if its overfilled being it in. I'm thinking the fuel treatment should fixit - I'm gonna drain the water from the filter too. I'll let you know.

i get this i took mine in no codes and they couldnt duplicate it but the truck only doesent afters it been run not when 1st started.... leads me to believe egr is causing it

I took mine in last week, they rushed through it reflashed the ecm and couldn't find a problem. Big supprise there. I picked it up and in the parking lot the cel came on. MAF sensor. It's going back monday for another look.

I had the same problem through out October, took it in to the stealer and they charged me $100 to check. Couldn't find anything they said. I went home and finally disabled my egr with EFILive, problem went away. I think the EGR at warm conditions was holding itself open farther than before causing the truck to run rough.

im going to unplug mine here in about an hour

Here I was knocking on wood hoping everything was OK, when all of a sudden the problem occured again. I just had my CAT and Stock muffler removed today, went for a small cruise afterwards and pulled into the drive thru for some supper and the truck started idling rough and pouring our tons of blue smoke in drive. Put it in neutral and the problem subsided, back in gear tons of smoke and rough idle. Drove it around for a while and stopped at a few lights the problem just went away. IS it possible the EGR could be floating open? I know it's not the fuel filter less than 1000 miles on it plus I have a 2nd one in front of the factory one.

Here I was knocking on wood hoping everything was OK, when all of a sudden the problem occured again. I just had my CAT and Stock muffler removed today, went for a small cruise afterwards and pulled into the drive thru for some supper and the truck started idling rough and pouring our tons of blue smoke in drive. Put it in neutral and the problem subsided, back in gear tons of smoke and rough idle. Drove it around for a while and stopped at a few lights the problem just went away. IS it possible the EGR could be floating open? I know it's not the fuel filter less than 1000 miles on it plus I have a 2nd one in front of the factory one.

Maybe we're finally getting somewhere on this - my problem started very soon after I ditched my cat, blocked my egr and installed a fingers stick. Also happened to coincide with the availablility of ULSD fuel in my area. My problem is exactly like yours - occasionally when I'm idleing in gear the idle will get rough and I start belching smoke - put in nuetral and it stops - give it a little throttle and it stops again. Can anybody figure this out?:confused:

mine quit after i unplugged mine today

runs great now :)

OK - my EGR blocker is coming out tomorrow and we'll see how we do. Thanks!

I don't have my EGR blocked yet. The problem hasn't occured since last week though.

I still have my EGR Tuned Off with EFILive, I filled up just on friday and poured a whole bunch of conditioner in the truck, 1/2 a bottle. Truck runs better, strange I always use conditioner everytime I fill up and still the problem existed. Will monitor and post anything different. To me it's either the EGR floating open or bad fuel. I am considering installing a blocker plate.

OK - my EGR blocker is coming out tomorrow and we'll see how we do. Thanks!

I have had my EGR blocked since the truck was practically new and have had no problems yet. It will be interesting to see if removing the blocker fixes your problem. If it does, I will be interested to find out why. Good luck.