Rough idle ---smokin

[GeorgiaDiesel]

2004.5 dura crewcab 4x4 30,000 miles. It has happened twice now been sitting at idle and the truck will start running rough and after about 15 to 20 seconds evens itself out then a large plum of smoke comes out of the exhaust. Truck goes back to normal no problems. Took to dealer and he got back a bulletin from GM that stated that if could not locate problem look at aftermarket exhaust and air filter. I have stainless steel exhaust no cat and K&N filter....Whats UP?

[glendonboy]

I'm just a newbie, but there are alot of posts here on the K&N filters causing issues with sensors because of the oil from the filter. I have a new lly with 700 miles, so I would be interested in this post as well.

[Kennedy]

I've seen them do that stock also. Almost like the EGR is acting up or being too aggressive trying to get the results that it wants. Is your EGR functional?