inconsistant smoking

Trucks with lazy or weak DOC will start to smoke like this when the unit is regening. Since the regen happens only when the system is needing one, it can be a hit and miss phenomena. One way to know if it is regen related is to come to stop when you notice the smoke. During a regen the high exhaust temp light will come if the truck is moving at less than 5 mph. If you stop and the exhaust temp light is on you know it was doing a regen.

 

What color is the smoke?

 

White is usually coolant.....blue usually oil. Burning coolant burns the #### out of your eyes.....useless test on a truck with stacks tho lol

 

Heavy d probably has the right answer .. Also when pulling a hill or a heavy load you make more exhaust heat which starts a passive burn if needed .. I've seen a few guys I know smoke bluish when a passive burn is just starting but once going it cleans up .. My guess is shortly after you notice bluish smoke truck pulls better due to dpf being less restrictive after burn off

 

Like heavyd said, sounds like a rolling regen. The 2010s still dumped fuel down the exhaust to heat up the DPF.

 

Might have a clogged EGR cooler, or DPF filter ..

 

I agree See this quite a lot.