This tool provides general guidance — not professional mechanical advice. Always have a qualified mechanic inspect your vehicle before making any repair decisions.
#1 Most Likely
Check engine light flashing
Typical Cost
$213 – $2,500
Ignition coil replacement typically costs $213–$383 per coil per industry repair data (2024). If catalytic converter damage results from prolonged misfiring, replacement may cost $900–$2,500. Stop driving and have towed if the light is actively flashing. Prices vary by vehicle make and region.
Wide range because the exact repair depends on what's causing the symptom.
- Failed ignition coil causing cylinder misfire
- Fouled or failed spark plug
- Leaking fuel injector causing raw fuel in cylinder
- Intake or exhaust valve failure causing compression loss
A flashing (blinking) check engine light indicates an active, severe engine misfire. An active misfire allows unburned fuel to enter the catalytic converter, which can overheat the converter and cause irreversible damage within minutes. Continued driving with a flashing CEL risks a catalytic converter failure that may cost $900–$2,500 to replace — in addition to repairing the underlying misfire.
What a mechanic will check
A mechanic will likely read misfire fault codes to identify which cylinder is misfiring, perform an ignition coil spark test, check spark plug condition, and inspect for signs of injector failure. They may also test for a compression or valve issue if basic ignition components check out.
What to say to your mechanic
“My check engine light is flashing — not solid. I know this means an active misfire. Can you read the codes, check which cylinder is misfiring, and tell me the condition of my ignition coils and spark plugs? I want to understand the extent of the damage before we decide on repairs.”
Script based on industry repair procedures
Related Symptoms