POTENTIAL COMPLAINTS:
- Irregular engine running
- Loss of power
- Jerking
- Diagnostic trouble code P1444, P16786

Foreign bodies from the catalytic converter area can be sucked through the lines of the exhaust gas recirculation due to pulsations in the exhaust tract or the vacuum in the intake air system of petrol engines. If a foreign body blocks the EGR valve in open state, exhaust gas is permanently fed back. This results in the described complaints and error messages, such as
- P1444 position sensor EGR valve – area/function error
- P16786 EGR – throughput too high
The fault is often attributed to the air mass sensor if less supplied fresh air is measured than is calculated for this operating state.

These foreign bodies may be broken pieces of a damaged catalytic converter or welding beads from the catalytic converter production. Check the catalytic converter for damage, e.g. using an endoscope through the opening of the control sensor in front of the catalytic converter and replace the EGR valve.