Typical repair cost: $50–$3,500
Run your why is my check engine light flashing? jobs in Repairius.
Estimates, text approvals, invoices and payments in one place, with unlimited users. Need a shop instead? Browse local providers and call them directly.
Flashing CEL specifically means cylinder misfire severe enough to damage the catalytic converter — codes P0300-P0312.
#1 cause of sudden flashing CEL — single coil dies and dumps fuel into the cat.
Stuck-open or dead injector floods or starves a cylinder.
Burnt valve or broken spring shows as persistent single-cylinder misfire.
A flashing CEL means damage is happening NOW — every minute of driving costs you catalytic converter life ($800-$3,000).
Doing it yourself? Shop our partners
We may earn a small commission from partner links — it never changes the price you pay.
Repairius keeps estimates, work orders, real-time job assignment, customer and vehicle history, inventory, and payments in one place — on desktop and in your pocket.
14-day free trial · credit card required · cancel anytime
Not a mechanic? Send Repairius to your shop — they can run estimates, jobs, and invoices in one place.
Share this page with a mechanic, a shop owner, or a friend working on the same problem.