Answer to: Repairing the injectors - clean or replaceI had a similar issue with my 2002 Duramax. Smoke on idle, little bit of a puff upon acceleration and then no problems when cruising along. I solved my problem by: 1) Running the engine to operating temperature. 2) Removing the fuel filter and putting in a new one. 3) Filling the reservoir with "Sea Foam" (a cleaner you can buy at any auto parts shop) 4) Re-installing the fuel filter housing. 5) Idle the engine for 3 minutes. 6) Let it sit for 20 minutes. 7) Run for 3 minutes. 8) Let it sit for 20 minutes. 9) Run the truck hard (up hills / tow a trailer) for 20 minutes. This Sea Foam was able to hot soak my injectors twice and broke up whatever was clogging one (or more) of my injectors. Cost: $10 for Sea Foam $35 for new diesel filter.