Hi - I have prius 2010 98000 driven. I had P0401 with check engine light. Got Egr cleaned along with pipes, throttle body n MAP sensor. I didnt clean the intake manifold after opening, but client the passage it has to egr. Now the light is back almost about after 100k. What next should be done?
You should clean the intake manifold too. There are four small return secondary ports that can clogged up with grime. Additional questions: Does your engine consume oil? Was the PCV valve replaced? You mentioned EGR cleaned. Does it include the EGR cooler?
You need to clean the whole egr system. It’s probably clogged with carbon. I would clean the egr cooler, pipe and intake manifold. If you cleaned it once before with the code and it went away, and now it has return, it’s probably has a build up of carbon over time.
While the valve is covered, that replacement won’t solve the underlying cause. Stories here point to the valve getting replaced, but everything else in the circuit being left “as-is”. Cleaning the circuit is the best solution for the symptom .
