6.6 Duramax Running Rough / Misfire


Several things could be causing rough running or a misfire in your 6.6L Duramax

Problem: Stiction (clogged injectors)

Solution: Treat with Stiction Eliminator to clear out stiction.

Problem: Mechanically failing injector(s)


The LB7 trucks were notorious for injector failure. A rough-running engine can mean that there is an injector that has broken beyond the point of our product cleaning it.
An electrical issue, such as a sensor failure (e.g., ICP sensor), can affect your truck in a similar way. You will need a scan tool to properly diagnose this.

The hardest to diagnose is an intermittent miss. It may be best to take the vehicle to a professional, depending on how good you are with your vehicles electrical system.

If you have any questions, feel free to contact one of our diesel experts.

The contents of, such as text, graphics, images, and other material contained on the Diagnose Your Diesel section are for informational purposes only. Always seek the advice of your mechanic or other qualified professional with any questions you may have regarding your vehicle’s condition.