Abstract We study the chameleon field dark matter. dubbed scalaron. in F (R) gravity in the Big Bang Nucleosynthesis (BBN) epoch. With an R 2-correction term required to solve the singularity problem for F (R) gravity. https://www.roneverhart.com/MagnaFlow-2001-2005-Honda-Civic-Street-Series-Cat-Back-Performance-Exhaust-System/