Emissions Codes
704 OBD-II diagnostic trouble codes in this category.
Showing page 5 of 8 (704 codes total)
| Code | Description | Subsystem | Severity |
|---|---|---|---|
| P2271 | O2 Sensor Signal Biased/Stuck Rich Bank 1 Sensor 2 | Oxygen Sensor | Medium |
| P2272 | O2 Sensor Signal Biased/Stuck Lean Bank 2 Sensor 2 | Oxygen Sensor | Medium |
| P2273 | O2 Sensor Signal Biased/Stuck Rich Bank 2 Sensor 2 | Oxygen Sensor | Medium |
| P2274 | O2 Sensor Signal Biased/Stuck Lean Bank 1 Sensor 3 | Oxygen Sensor | Medium |
| P2275 | O2 Sensor Signal Biased/Stuck Rich Bank 1 Sensor 3 | Oxygen Sensor | Medium |
| P2276 | O2 Sensor Signal Biased/Stuck Lean Bank 2 Sensor 3 | Oxygen Sensor | Medium |
| P2277 | O2 Sensor Signal Biased/Stuck Rich Bank 2 Sensor 3 | Oxygen Sensor | Medium |
| P2278 | O2 Sensor Signals Swapped Bank 1 Sensor 3/Bank 2 Sensor 3 | Oxygen Sensor | Medium |
| P2280 | Air Flow Restriction/Air Leak Between Air Filter and MAF Bank 1 | Emission Control | Medium |
| P2281 | Air Leak Between MAF and Throttle Body | Emission Control | Medium |
| P2282 | Air Leak Between Throttle Body and Intake Valves | Emission Control | Medium |
| P2283 | Injector Control Pressure Sensor Circuit | Emission Control | Medium |
| P2284 | Injector Control Pressure Sensor Circuit Range/Performance | Emission Control | Medium |
| P2285 | Injector Control Pressure Sensor Circuit Low | Emission Control | Medium |
| P2286 | Injector Control Pressure Sensor Circuit High | Emission Control | Medium |
| P2287 | Injector Control Pressure Sensor Circuit Intermittent | Emission Control | Medium |
| P2288 | Injector Control Pressure Too High | Emission Control | Medium |
| P2289 | Injector Control Pressure Too High - Engine Off | Emission Control | Medium |
| P2292 | Injector Control Pressure Erratic | Emission Control | Medium |
| P2293 | Fuel Pressure Regulator B Performance | Emission Control | Medium |
| P2294 | Fuel Pressure Regulator B Control Circuit/Open | Emission Control | Medium |
| P2295 | Fuel Pressure Regulator B Control Circuit Low | Emission Control | Medium |
| P2296 | Fuel Pressure Regulator B Control Circuit High | Emission Control | Medium |
| P2297 | O2 Sensor Out of Range During Deceleration Bank 1 Sensor 1 | Oxygen Sensor | Medium |
| P2298 | O2 Sensor Out of Range During Deceleration Bank 2 Sensor 1 | Oxygen Sensor | Medium |
| P2299 | Brake Pedal Position/Accelerator Pedal Position Incompatible | Emission Control | Medium |
| P22AB | O2 Sensor Positive Current Control Circuit/Open Bank 1 Sensor 2 | Oxygen Sensor | Medium |
| P22AC | O2 Sensor Positive Current Control Circuit Low Bank 1 Sensor 2 | Oxygen Sensor | Medium |
| P22AD | O2 Sensor Positive Current Control Circuit High Bank 1 Sensor 2 | Oxygen Sensor | Medium |
| P22AE | O2 Sensor Reference Voltage Circuit/Open Bank 1 Sensor 2 | Oxygen Sensor | Medium |
| P22AF | O2 Sensor Reference Voltage Performance Bank 1 Sensor 2 | Oxygen Sensor | Medium |
| P22B0 | O2 Sensor Reference Voltage Circuit Low Bank 1 Sensor 2 | Oxygen Sensor | Medium |
| P22B1 | O2 Sensor Reference Voltage Circuit High Bank 1 Sensor 2 | Oxygen Sensor | Medium |
| P22B2 | O2 Sensor Negative Current Control Circuit/Open Bank 1 Sensor 2 | Oxygen Sensor | Medium |
| P22B3 | O2 Sensor Negative Current Control Circuit Low Bank 1 Sensor 2 | Oxygen Sensor | Medium |
| P22B4 | O2 Sensor Negative Current Control Circuit High Bank 1 Sensor 2 | Oxygen Sensor | Medium |
| P22B5 | O2 Sensor Pumping Current Trim Circuit/Open Bank 1 Sensor 2 | Oxygen Sensor | Medium |
| P22B6 | O2 Sensor Pumping Current Trim Circuit Low Bank 1 Sensor 2 | Oxygen Sensor | Medium |
| P22B7 | O2 Sensor Pumping Current Trim Circuit High Bank 1 Sensor 2 | Oxygen Sensor | Medium |
| P22B8 | O2 Sensor Positive Current Control Circuit/Open Bank 2 Sensor 2 | Oxygen Sensor | Medium |
| P22B9 | O2 Sensor Positive Current Control Circuit Low Bank 2 Sensor 2 | Oxygen Sensor | Medium |
| P22BA | O2 Sensor Positive Current Control Circuit High Bank 2 Sensor 2 | Oxygen Sensor | Medium |
| P22BB | O2 Sensor Reference Voltage Circuit/Open Bank 2 Sensor 2 | Oxygen Sensor | Medium |
| P22BC | O2 Sensor Reference Voltage Performance Bank 2 Sensor 2 | Oxygen Sensor | Medium |
| P22BD | O2 Sensor Reference Voltage Circuit Low Bank 2 Sensor 2 | Oxygen Sensor | Medium |
| P22BE | O2 Sensor Reference Voltage Circuit High Bank 2 Sensor 2 | Oxygen Sensor | Medium |
| P22BF | O2 Sensor Negative Current Control Circuit/Open Bank 2 Sensor 2 | Oxygen Sensor | Medium |
| P22C0 | O2 Sensor Negative Current Control Circuit Low Bank 2 Sensor 2 | Oxygen Sensor | Medium |
| P22C1 | O2 Sensor Negative Current Control Circuit High Bank 2 Sensor 2 | Oxygen Sensor | Medium |
| P22C2 | O2 Sensor Pumping Current Trim Circuit/Open Bank 2 Sensor 2 | Oxygen Sensor | Medium |
| P22C3 | O2 Sensor Pumping Current Trim Circuit Low Bank 2 Sensor 2 | Oxygen Sensor | Medium |
| P22C4 | O2 Sensor Pumping Current Trim Circuit High Bank 2 Sensor 2 | Oxygen Sensor | Medium |
| P22E2 | Cylinder 3 Alternative Fuel Injector Control Circuit Low | Emission Control | Medium |
| P23A0 | O2 Sensor Exhaust Sample Error Bank 1 Sensor 2 | Oxygen Sensor | Medium |
| P23A1 | O2 Sensor Exhaust Sample Error Bank 2 Sensor 2 | Oxygen Sensor | Medium |
| P2400 | EVAP Leak Detection Pump Control Circuit/Open | EVAP System | Medium |
| P2401 | EVAP Leak Detection Pump Sense Circuit/Open | EVAP System | Medium |
| P2402 | EVAP Leak Detection Pump Control Circuit Low | EVAP System | Medium |
| P2403 | EVAP Leak Detection Pump Control Circuit High | EVAP System | Medium |
| P2404 | EVAP Leak Detection Pump Sense Circuit Range/Performance | EVAP System | Medium |
| P2405 | EVAP System Leak Detection Pump Sense Circuit Low | EVAP System | Medium |
| P2406 | EVAP System Leak Detection Pump Sense Circuit High | EVAP System | Medium |
| P2407 | EVAP System Leak Detection Pump Sense Circuit Intermittent/Erratic | EVAP System | Medium |
| P2408 | Fuel Cap Sensor/Switch Circuit | Emission Control | Medium |
| P2409 | Fuel Cap Sensor/Switch Circuit Range/Performance | Emission Control | Medium |
| P2410 | Fuel Cap Sensor/Switch Circuit Low | Emission Control | Medium |
| P2411 | Fuel Cap Sensor/Switch Circuit High | Emission Control | Medium |
| P2412 | Fuel Cap Sensor/Switch Circuit Intermittent/Erratic | Emission Control | Medium |
| P2413 | EGR System Performance | Emission Control | Medium |
| P2414 | O2 Sensor Exhaust Sample Error Bank 1 Sensor 1 | Emission Control | Medium |
| P2415 | O2 Sensor Exhaust Sample Error Bank 2 Sensor 1 | Emission Control | Medium |
| P2416 | O2 Sensor Signals Swapped Bank 1 Sensor 2/Bank 1 Sensor 3 | Emission Control | Medium |
| P2417 | O2 Sensor Signals Swapped Bank 2 Sensor 2/Bank 2 Sensor 3 | Emission Control | Medium |
| P2418 | EVAP System Switching Valve Control Circuit/Open | EVAP System | Medium |
| P2419 | EVAP System Switching Valve Control Circuit Low | EVAP System | Medium |
| P2420 | EVAP Switching Valve Control Circuit/Open | EVAP System | Medium |
| P2421 | EVAP System Vent Valve Stuck Open | EVAP System | Medium |
| P2422 | EVAP Vent Valve Stuck Closed | EVAP System | Medium |
| P2423 | HC Adsorption Catalyst Efficiency Below Threshold Bank 1 | Emission Control | Medium |
| P2424 | HC Adsorption Catalyst Efficiency Below Threshold Bank 2 | Emission Control | Medium |
| P2425 | EGR Cooling Valve Control Circuit/Open | Emission Control | Medium |
| P2426 | EGR Cooling Valve Control Circuit Low | Emission Control | Medium |
| P2427 | EGR Cooling Valve Control Circuit High | Emission Control | Medium |
| P2428 | Exhaust Gas Temperature Too High Bank 1 | Emission Control | Medium |
| P2429 | Exhaust Gas Temperature Too High Bank 2 | Emission Control | Medium |
| P2430 | AIR System Air Flow/Pressure Sensor Circuit Bank 1 | Emission Control | Medium |
| P2431 | Secondary Air Injection System Air Flow/Pressure Sensor Circuit Bank 1 | Secondary Air | Medium |
| P2432 | Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1 | Secondary Air | Medium |
| P2433 | AIR System Air Flow/Pressure Sensor Circuit High Bank 1 | Emission Control | Medium |
| P2434 | AIR System Air Flow/Pressure Sensor Circuit Intermittent/Erratic Bank 1 | Emission Control | Medium |
| P2435 | AIR System Air Flow/Pressure Sensor Circuit Bank 2 | Emission Control | Medium |
| P2436 | AIR System Air Flow/Pressure Sensor Circuit Range/Performance Bank 2 | Emission Control | Medium |
| P2437 | AIR System Air Flow/Pressure Sensor Circuit Low Bank 2 | Emission Control | Medium |
| P2438 | AIR System Air Flow/Pressure Sensor Circuit High Bank 2 | Emission Control | Medium |
| P2439 | AIR System Air Flow/Pressure Sensor Circuit Intermittent/Erratic Bank 2 | Emission Control | Medium |
| P2440 | Secondary Air Injection System Switching Valve Stuck Open Bank 1 | Secondary Air | Medium |
| P2441 | Secondary Air Injection System Switching Valve Stuck Closed Bank 1 | Secondary Air | Medium |
| P2442 | AIR System Switching Valve Stuck Open Bank 2 | Emission Control | Medium |
| P2443 | AIR System Switching Valve Stuck Closed Bank 2 | Emission Control | Medium |
| P2444 | Secondary Air Injection System Pump Stuck On Bank 1 | Secondary Air | Medium |
About Emissions Codes
This page lists all 704 OBD-II diagnostic trouble codes classified under the Emissions category. These codes are stored by your vehicle's onboard computer when a sensor detects a malfunction in the emissions system. Each code begins with a letter indicating the system (P for Powertrain, B for Body, C for Chassis, U for Network) followed by four digits that identify the specific fault.
When your check engine light comes on, an OBD-II scanner reads these stored codes to help pinpoint the problem. Generic codes (where the second digit is 0) follow the SAE J2012 standard and mean the same thing on every vehicle. Manufacturer-specific codes (where the second digit is 1) may have different meanings depending on the vehicle brand.
Click any code in the table above to see its full description, possible causes, common symptoms, and step-by-step repair guidance. Use the search box to quickly find a specific code within this category.