Was thinking about all the problems the EGR system causes in these cars and (without taking the time to check) I wondered if there was ever any indication that cleaning the cooler and intake manifold was ever something Toyota recommended? Was this system supposed to be maintenance free? Only asking because I learned about it on Priuschat and have talked to owners that look at me like I am crazy, meanwhile their cars are ticking time bombs.
If the EGR system is not working correctly, the ECU will trigger trouble codes P0401 or P0403. What will not be detected is if there is reduced flow or a blockage in one or more of the four small EGR passageways that are in the intake manifold. If this occurs, you will have uneven EGR flow into the four cylinders on the engine.
My newly acquired Prius couldn’t pass cleaning solution through the cooler and the intake ports looked completely gunked. I guess asking why it doesn’t become a maintenance item or is there more to Toyota admitting there is an issue? may be similar to my Honda Odyssey that has the VCM that shuts down cylinders to get about 1mpg better that the standard engine. It’s known to be so detrimental that there is several suppliers of products and trick the motor into never shutting down the cylinders to preserve engine life and motor mounts. Honda will never tell people to disable that nor do they provide any guidance
Toyota may or may not have know it was going to be an issue. Remember, car manufacturers really only care about the car making it to the end of the warranty. Then you buy another car. Usually these issue start showing up after after 100,000 and more miles. EVERY car needs maintainence. Everyone manufaturer has a vehicle that has not met there standard.
On Gen3, equipped with the EGR system, a greater number of errors are possible in the event of a malfunction of the gas recirculation. These include misfires, engine failure to start, and other errors.
