The catalytic converter is likely one of the most important emission control devices on a vehicle, being that its purpose is to clean up pollutants in exhaust. Most late-model OBD-II converters should last upward of 150,000 miles under normal driving conditions, making converter replacement a job that shops only perform about twice a month, on average. However, eventually, these parts will fail, and when it comes time to restock, shops that responded to the Counterman Professional Automotive Repair Technician Survey (P.A.R.T.S.) reported that they rely on an average of 2.7 sources for this part. Thirty-five percent pick jobbers as their primary source for catalytic converters, with 41 percent saying best sales reps are what keep them coming back to their first call.