Both Walker, 40, and Rodas, 38, tested negative for alcohol, and drugs including cocaine, opiates and marijuana were not detected, said the report from the Los Angeles County coroner's office.
The report included an early account of the accident from the Los Angeles Sheriff's Department, dated December 1 - the day after the crash, saying the Porsche Carrera GT driven by Rodas was traveling at "an unsafe speed, approximately 100+ mph."
But a sheriff's spokeswoman said the investigation into the accident has not been completed and there was no definitive finding on the car's speed.
Both deaths were ruled accidents. Walker died from "combined effects of traumatic and thermal injuries," and Rodas from "multiple traumatic injuries," the report said.
Walker was in the process of filming "Fast & Furious 7" at the time and production was halted a few days later.
Universal Pictures said last month that the release of the seventh installment in the highly lucrative franchise would be pushed back by nine months to April 2015. Walker will appear in the film.