21/02/2026
Another interesting diagnostic and repair last week. Had a 2016 Mazda Cx-5 with a check engine light and P0401 EGR insufficient flow code. Found the EGR cooler to be completely blocked with carbon and the intake manifold also.
Fitted a new EGR Cooler along with removing the intake manifold, cleaning it, the throttle body, both EGR valves and the intake runners inside the head.
Carbon build up wasn't caused by anything other then normal operation.
If you have any issues with your car, caravan, trailer etc feel free to reach out.
Kind regards
Stuart.