Most-Searched Engine Fault Codes
P0171 medium
System Too Lean (Bank 1)
O2 sensor on Bank 1 reports the air-fuel mixture is running leaner than the PCM's correcti…
P0300 high
Random / Multiple Cylinder Misfire
PCM detected misfires on multiple cylinders—no single cylinder is consistently misfiring.…
P0420 medium
Catalyst System Efficiency Below Threshold (Bank 1)
Downstream O2 sensor on Bank 1 is switching too actively — indicates cat is no longer stor…
P0128 low
Coolant Temperature Below Thermostat Regulating Temperature
ECT sensor reports coolant never reaches target operating temperature within expected driv…
P0442 low
Evaporative Emission System Leak Detected (Small Leak)
EVAP monitor detected a leak approximately 0.020" or smaller in the fuel vapor system.…
P0507 medium
Idle Air Control System RPM High
PCM commanded idle RPM is lower than actual idle speed — engine idles faster than target.…
Diagnose by Symptom
How OBDHacks Works
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STEP 01
Plug in Your Scanner
Any $20 OBDII Bluetooth adapter reads the fault code from your car's OBD port.
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STEP 02
Enter the Code Here
Paste the code above. Add your car make for brand-specific repair notes.
📋
STEP 03
Get Expert Diagnosis
Instant structured report: symptoms, causes ranked by probability, and exact repair steps.
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STEP 04
Fix It or Quote It
DIY the fix or walk into a shop knowing exactly what's wrong — no upsell possible.
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