At the annual conference of the National Association of Small Trucking Companies a couple weeks back in Nashville, TA Petro Truck Service VP Homer Hogg presented results from his analysis of recent-history fault codes seen by the three leading all-model diagnostic equipment providers. He analyzed codes data to determine the five biggest parts of the trucks those codes were related to.

At No. 1, probably no surprise, were aftertreatment-related codes, and his talk featured here then provided an informative look at persnickety emissions systems in 2010 and later trucks -- with actionable steps owner-operators and small fleets can take to guard against some of the most common issues seen.

Among the recommendations he makes:

**When the dashboard lights up, don’t clear those codes. Techs need them to properly diagnose any issue.

**Clean the DEF doser once a year, at least.

**Change your DEF filter according to manufacturer-recommended intervals.

**Keep a “clean room” approach around the DEF tank, particularly when you’re pumping the fluid.

**Keep SCR-system efficiency tests in mind to periodically examine it to prevent NOx sensor failures.

**Most importantly, perhaps, don’t fall for the "delete kit" trap, if you want qualified mechanics to be able to help you work issues out.

Other helpful emissions-related coverage: https://www.overdriveonline.com/overdrive-radio/podcast/15066117/emissions-maintenance-how-to-get-the-correct-diagnosis-repair

https://www.overdriveonline.com/equipment/article/15290372/how-to-delete-emissions-issues-without-breaking-the-bank

https://www.overdriveonline.com/maintenance/article/15540134/fuel-treatments-becoming-part-of-owneroperators-pm-routine