Ignoring a check engine light can cause more damage that eventually leads to more costly issues, according to CarMD. Their 2024 Vehicle Health Index reveals the cost to repair or replace the 10 most common damaged parts and systems that lead to a check engine light appearing. Here is their list of average costs (parts and labor) for inspection and replacement.

Catalytic converter: $1,304.21
Oxygen sensor: $252.62
Ignition coils and spark plugs: $398.27
Mass air flow sensor: $311.09
Ignition coils: $211.64
Evaporative emissions canister purge control valve: $140.90
Fuel tank cap, tighten or replace, if necessary: $25.20
ABS wheel speed sensor: $271.11
Fuel injectors: $445.62
Powertrain control module: $109.05