What each code actually costs to fix
Every range below is a reference range compiled from more than one source type, not a quote. The dealer column is left blank where we have no dealer data, because printing a number we cannot source is worse than printing nothing.
Codes that usually stay under $400
These are the ones where a sensor or a hose is the likely fix. Start here before you budget for anything bigger.
| Code | Shop | DIY | Parts | Confidence |
|---|---|---|---|---|
| P0128 Coolant Thermostat Below Regulating Temperature | $150–$400 | $20–$80 | 2 | editorial_estimate_wide |
| P0335 Crankshaft Position Sensor A Circuit | $150–$400 | $30–$120 | 1 | editorial_estimate_wide |
| P0455 Evaporative Emission System Leak Detected (Large Leak) | $80–$300 | $15–$120 | 2 | editorial_estimate_wide |
| P0135 O2 Sensor Heater Circuit (Bank 1 Sensor 1) | $150–$350 | $30–$100 | 1 | editorial_estimate_wide |
| P0456 Evaporative Emission System Leak Detected (Very Small Leak) | $90–$280 | $15–$80 | 2 | editorial_estimate_wide |
| P0442 Evaporative Emission System Leak Detected (Small Leak) | $80–$250 | $15–$100 | 2 | editorial_estimate_wide |
| P0113 Intake Air Temperature Sensor Circuit High | $100–$250 | $20–$60 | 1 | editorial_estimate_wide |
| P0118 Engine Coolant Temperature Sensor Circuit High | $100–$250 | $20–$60 | 1 | editorial_estimate_wide |
Codes that can run past $400
A wide range on these is honest, not evasive. The final bill depends on which part turns out to be the real cause, and that is what the diagnostic steps are for.
| Code | Shop | DIY | Parts | Confidence |
|---|---|---|---|---|
| P0700 Transmission Control System Malfunction | $100–$3,000 | $0–$50 | 2 | editorial_estimate_wide |
| U0100 Lost Communication With ECM/PCM | $100–$1,500 | $0–$60 | 2 | editorial_estimate_wide |
| P0016 Crankshaft / Camshaft Position Correlation (Bank 1) | $300–$1,500 | $0–$80 | 2 | editorial_estimate_wide |
| P0420 Catalyst System Efficiency Below Threshold (Bank 1) | $180–$1,200 | $45–$300 | 2 | editorial_estimate_wide |
| P0430 Catalyst System Efficiency Below Threshold (Bank 2) | $180–$1,200 | $45–$300 | 2 | editorial_estimate_wide |
| P0300 Random or Multiple Cylinder Misfire Detected | $120–$900 | $20–$250 | 3 | editorial_estimate_wide |
| P0011 Camshaft Position Timing Over-Advanced (Bank 1) | $200–$900 | $30–$120 | 2 | editorial_estimate_wide |
| P0301 Cylinder 1 Misfire Detected | $120–$700 | $20–$200 | 3 | editorial_estimate_wide |
| P0172 System Too Rich (Bank 1) | $100–$650 | $15–$200 | 3 | editorial_estimate_wide |
| P0171 System Too Lean (Bank 1) | $100–$600 | $10–$200 | 3 | editorial_estimate_wide |
| P0121 Throttle Position Sensor Range / Performance | $200–$600 | $30–$150 | 2 | editorial_estimate_wide |
| P0101 Mass Air Flow Sensor Range / Performance | $150–$500 | $20–$150 | 2 | editorial_estimate_wide |
How these numbers are built
Each range is a reference range: the envelope of at least two source types, which we label as parts catalog, independent labor estimate, or owner-reported spend. Confidence is high at three source types, medium at two, and single-source below that. Data is stamped with a month, and the stamp appears on every code page.
This is not a quote. Actual cost depends on your vehicle, your region, and which part turns out to be the real cause.