bad egr valve?
My truck has been running pretty bad lately, it has a whiteish/blue smoke and occoasionally (when acceleration) puffs black smoke. It all seems to be intermittant, cant seem to produce the symptoms. Today after fueling up and leaving the station the truck stumbled really bad when accelleration (all the way home, approx 3 miles) and at times smoked out the cars behind me with a whiteish smoke. The truck is throwing the P0405 code which says a problem with the EGR system. Would an egr problem cause the truck to run this way? What else could the problem be?