P0401 code after cleaning

You can take your car to somebody with text stream usually the dealer and see what it says when it's connected online to Toyota's network what updates any of the ECUs in your car need they'll show up in red and if you don't have them you can get all those updates flashed to your respective ECUs and then you're all updated from what I see I have a 2010 too and a 13 The pertinent updates to the ECUs and both of these cars didn't make much of a hullabaloo so I wouldn't think that's your problem there could be a sensor or whatever that sets this code I don't actually remember what this code is but either way it hasn't bothered me too much so we'll cross that bridge later.

 

Have you pulled the MAP sensor to make sure that the port that supplies vacuum to it is clear? Have you checked that the MAP sensor is accurate?

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That's the cat below threshold The converter has the converter ever been fooled within this car somebody tried to steal it play with it massage it a little? At this kind of mileage to try and abate that code the first thing I would do would be replacing the two O2 sensors by the correct parts put them in the correct place on the car up or down on the pipe and see what you got usually a lot of time just not the cat it's the sensors of just gotten old and now they are not able to discern between each other that they're reading correctly and you get this code or it happens every so often I've seen this happen to cars with the catalytic converter completely removed and it has gobs of flow from the manifold all the way out the tailpipe not prius's too so to me I believe it as something to do with the sensors not canceling each other out if you will

 

P0401 is "EGR flow insufficient detected". It is not related to the cat. (You might be thinking of P0420.)

It would be worthwhile to report the test value for the EGR flow monitor, as you can find described in this thread.

Another thing you can do is an active test to confirm flow and operation of the EGR valve. You can find the steps for that in the repair manual workup section for P0401.

 

Did you disassemble the EGR valve? Maybe something went awry during reassemble? Just guessing.

Anyway, here's some troubleshooting info:

 

FWIW I had a similar issue and what happened is I somehow managed to pinch the EGR gasket in such a way that it was obstructing the opening. I redid the gasket so it was set properly and disconnected the battery and the code has not come back. Like Mendel mentioned maybe something minuscule happened during reassembly. Start with the simple stuff and work your way down the list, it worked fine before cleaning so I'm sure it still works now.

 

did you get all 4 tiny ports in the im clean?

 

I apologize I didn't read your original post as closely as I should have. It appears the code was thrown BEFORE cleaning, correct?

If I were in your shoes I would do the following...
1) Ensure the EGR valve actually works, they stick sometimes. Some people can clean them and sometimes you just gotta replace them
2) If the EGR valve is good then remove the EGR tube (the metal one) and ensure it is unobstructed
3) Remove the intake manifold again and ensure the 4 passages to the EGR tube are unobstructed
4) Attempt to do an EGR flow test to see what is actually going on in there

 

i think you need tech stream:
techstream-egr-valve-blockage-data.206024

 

P0401 is an EGR flow issue. Your EGR flow monitor value (which is easy to check) has fallen below the allowable minimum.

Other then a cursory check of the valve to see that it opens and closes, any more attention lavished in that direction is probably less productive than looking for other reasons why the gases may not be flowing.

 

congrats!