Approximately 50% of the smog production in California can be attributed to only 10-15% of the light-duty vehicles; this is particularly true in the historically polluted and car-dependent San Joaquin Valley (SJV) region. Recent studies have found several adverse health impacts associated with exposure to heavily polluted air in the SJV. To improve air quality and the lives of SJV residents, an incentive program called Tune In & Tune Up (TI&TU) provides individuals with free emission testing and vouchers for smog repair at a series of publicly-held events. Since 2012, TI&TU has grown substantially, distributing $12 million in redeemed smog repair vouchers. It is currently California's largest transportation-focused environmental justice initiative in terms of participation, but has not yet been evaluated for health impacts and related cost-effectiveness. The purpose of this study is to estimate the annual and cumulative health and monetary benefits of the TI&TU program, using five years of emission reduction data from 18,000 repaired cars, and drawing from recently published environmental health methods. This study uses existing data on nitrogen oxides (NOx) annual emission reductions for each TI&TU vehicle to estimate the premature deaths avoided due to reduced NOx exposure in the SJV. First, the NOx reductions are converted into changes in nitrate particulate matter concentrations (PM2.5). These values will be used to estimate the number of premature deaths avoided due to reduced PM2.5 exposure, using a well-established health impact function. The monetary benefits related to health will be calculated using the Environmental Protection Agency's Environmental Benefits Mapping and Analysis Program, and Geographic Information Systems will be used to analyze and map geospatial differences at the census tract and county level. This interdisciplinary research is at the nexus of transportation equity, health, and environmental justice, and will provide insights regarding the tradeoffs and synergies between these objectives.