Ive posted on a couple of threads and no one seems to have any idea what would cause this. I just got home today after a second trip to the dealer and no problems were detected. My symptoms are light smoke on takeoff- extremely light throttle application, even through the neighborhood at 15-20 mph. Also more than normal smoke on acceleration around town and on the highway-even at cruise. And if I lay into her and come to a stop I can hear an injector like knock when she idles down followed by a clacking sound for a second or two. I've driven the truck 15k miles without these symptoms and I'm wondering if I've got some carboned injectors retarding the timing some or what? I've changed the fuel filter, cleaned the air filter, changed the oil and had it in the dealer twice(different ones) to no avail, any ideas the dealer didn't catch, bad MAP or otherwise? 
