The P0128 diagnostic trouble code indicates that the engine is not reaching its normal operating temperature quickly enough.

In simple terms, the engine is running too cold, usually because the thermostat is stuck open.

When the P0128 code appears, the Check Engine Light turns on, and fuel economy may decrease.

This is one of the most common OBD2 codes found on modern gasoline engines worldwide.

The P0017 diagnostic trouble code indicates a timing correlation problem between the crankshaft position sensor and the camshaft position sensor on Bank 1 Sensor B.

In simple terms, the engine timing is out of alignment.

This code is considered serious, as it may indicate timing chain stretch, VVT actuator failure, or internal engine timing issues.

When P0017 appears, the Check Engine Light will turn on, and the vehicle may run rough, lose power, or fail to start.

The P0016 diagnostic trouble code indicates a problem with the correlation between the crankshaft position sensor and the camshaft position sensor on Bank 1.

In simple terms, the engine timing is out of sync.

When P0016 appears, your Check Engine Light will illuminate, and the vehicle may experience rough running, poor acceleration, or even failure to start.

This code is considered serious because it may indicate internal engine timing problems.

The P2195 diagnostic trouble code indicates that the oxygen sensor (O2 sensor) located on Bank 1 Sensor 1 is reporting a constantly lean condition.

In simple terms, the engine control module (ECM) believes the engine is running with too much air and not enough fuel, or the sensor itself is malfunctioning.

When P2195 appears, your Check Engine Light will illuminate, and you may notice rough idle, poor acceleration, or reduced fuel efficiency.

This is a common code on modern fuel-injected engines and often appears together with other fuel-trim or airflow-related codes.

The P0442 diagnostic trouble code indicates that the vehicle’s EVAP (Evaporative Emission Control) system has detected a small leak.

In simple terms, this means fuel vapors are escaping from the sealed fuel system.

When P0442 appears, the Check Engine Light will turn on.
In most cases, there are no major drivability problems, but the issue should still be repaired.

The P0420 diagnostic trouble code indicates that the catalytic converter on Bank 1 is not operating efficiently.

In simple terms, this means the catalytic converter is not properly reducing harmful exhaust emissions.

When the P0420 code appears, your Check Engine Light will turn on.
In most cases, the vehicle may still drive normally, but the issue should not be ignored.

P0420 is one of the most common emissions-related trouble codes worldwide.

The P0101 diagnostic trouble code indicates that the engine control module (ECM) has detected an issue with the Mass Air Flow (MAF) sensor performance.

This means the MAF sensor readings are outside the expected range compared to engine load, throttle position, and RPM.

When the P0101 code appears, your Check Engine Light will turn on, and the vehicle may experience reduced performance, rough idle, or poor fuel economy.

P0101 is one of the most common airflow-related OBD2 trouble codes worldwide.

Here are standard and unique error codes for the Citroen Ds3, received through the on-board diagnostic connector of the OBD-II system of the car, with a brief decoding.

The P0171 diagnostic trouble code indicates that the engine control module (ECM) has detected a lean air-fuel mixture on Bank 1 of the engine.

In simple terms, this means the engine is receiving too much air and not enough fuel.

When P0171 appears, your Check Engine Light will turn on, and the vehicle may begin to run rough, hesitate during acceleration, or consume more fuel than usual.

This is one of the most common OBD2 codes on gasoline engines worldwide.

The P0300 diagnostic trouble code indicates that the engine control module (ECM) has detected random or multiple cylinder misfires.

When this code appears, your Check Engine Light will usually turn on, and the vehicle may run rough, shake, or lose power.

P0300 is one of the most common OBD2 codes found on gasoline engines worldwide.