Typical repair cost: $0–$1,200
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The most common cause. A loose cap triggers an evaporative-emissions (EVAP) code such as P0455.
Worn O2 sensors are the #1 long-tail cause and reduce fuel economy 15-40%.
Often caused by ignoring an earlier code; usually presents as P0420 or P0430.
Dirty or failed MAF causes hesitation, stalling, and codes like P0101.
Triggers misfire codes (P0300-P0308) — a flashing CEL means do not keep driving.
See a mechanic now if the light is flashing, the engine is running rough, or you smell raw fuel — continued driving can destroy the catalytic converter.
Oxygen Sensor Replacement Cost
Typical price range
EGR Valve Replacement Cost
Typical price range
Fuel Injectors info
100,000-150,000 miles (less on dirty fuel)
Oxygen (O2) Sensor info
60,000-100,000 miles
Spark Plugs info
Copper 20k-30k mi; platinum 60k-80k mi; iridium 100k-120k mi
All vehicle problems
OBD-II code lookup
Repair cost guides
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