EGR failure, what next?

EGR (Exhaust Gas Recirculation) is an exhaust gas recirculation system used in cars to reduce emissions of harmful substances such as nitrogen dioxide (NOx) and carbon oxides (CO).

The system works by recirculating some of the exhaust gas back into the combustion chamber, which reduces the temperature and amount of oxygen supplied to the engine. As a result, the amount of nitrogen dioxide produced during combustion is reduced.

The most common errors accompanying EGR system failures

For exhaust gas recirculation (EGR) valve faults, the most common DTCs are:

1. Errors related to incorrect operation of the EGR valve:

P0400 : Incorrect EGR flow.

P0401 : EGR flow too low.

P0402 : EGR flow too high.

P0403 : EGR valve control circuit problem.

P0404 : EGR valve range/operation incorrect.

P0405 : EGR position sensor voltage too low.

P0406 : EGR position sensor voltage too high.

2. Errors related to the exhaust gas temperature sensor:

P0410 : Exhaust gas temperature sensor indicates an operation error in the EGR system.

P2031 : Exhaust gas temperature sensor before EGR system incorrect.

P2032 : Signal from exhaust gas temperature sensor too low.

3. Throttle or air flow related errors:

P0299 : Boost pressure problem (indirectly related to EGR).

P0101 : Mass Air Flow (MAF) sensor problem - affecting EGR operation.

P0105 : Intake manifold pressure (MAP) sensor problem.

4. Errors related to the EGR control electrical system:

P0489 : EGR valve control signal low.

P0490 : EGR valve control signal high.

P2141 : EGR valve electrical circuit problem.

5. System errors related to EGR:

P1404 : EGR valve stuck in the closed position.

P1406 : EGR valve stuck in the open position.

P1497 : EGR valve position adjustment problem.

6. DPF related errors and their connection with EGR:

P242F : Too high soot level in the DPF filter (indirectly related to EGR failure).

P2002 : Insufficient DPF efficiency - possible cause is EGR damage.

7. Other errors:

P2413 : Incorrect EGR/DPF system performance.

P2457 : EGR cooler problem - incorrect performance.

Causes of these errors:

Accumulation of soot and dirt in the EGR channel.

EGR valve stuck (in open or closed position).

Electrical or mechanical damage to the EGR valve.

Problems with exhaust or air flow sensors.

Regular cleaning or replacing the EGR valve and maintaining the DPF filter and intake system can help avoid most of these problems. It is also worth considering possible dependencies between systems during diagnostics.