The California Bureau of Automotive Repair has "the Consumer Assistance Program’s (CAP) repair assistance option, which offers eligible consumers whose vehicles fail a biennial Smog Check inspection financial assistance toward emissions-related repairs at a STAR test-and-repair station. Owners of model year 1996 or newer vehicles may receive up to $1,200 in emissions-related repairs. Owners of model year 1976 through 1995 vehicles may receive up to $900 in emissions-related repairs."

You can go to their website to review the eligibility requirements and online application: https://www.bar.ca.gov/Consumer/Consumer_Assistance_Program/CAP_Repair_Assistance_Program.aspx