insufficient EGR flow, P0401 Options

[Tsizzles98]

So my 98 celica gt has been throwin me this code for about 2 weeks now and its not staying away.
I have cleaned the port on the throttle body, cleaned the vacumm line ports on the throttle body, replaced egr valve, tested the vacumm modulator (item to the left of the egr with a filter in it), and tested the vsv which is a purge solenoid on the lower part of then engine (ecm tell it when to allow vacumm to open egr
i did all of this and yet i keep getting the code
now my last suspects are either the map sensor or ecm
now with the map sensor im sure it would run funny and all if it went bad, but the car runs fine
and ecms dont go bad often
so can any one help me, im taking any suggestion at this point.

[Johnnyny]

did you disconnect the battery after you did all dat to erase the code and drive around

[Tsizzles98]

ive cleared the code after every time i try to fix it, and it comes right back on, now i just got done reading a thread about replacving the modulator, so i think thats my next step.

[Smaay]

im getting both codes at the same time, excessive and insufficient. its very fustrating.

[Tsizzles98]

I actaully seen something for both codes at the same time on all data, if you have ever heard of that. Ill read up on it it and post what I find

[Smaay]

please do, its very fustrating!

[samir0189]

the egr is a pain to diagnose. My CEL has been on and off with insufficient egr flow. It doesn't seem to affect anything, so I just let it be.

However, my specific problem seems to relate to the fuel gauge reading.... strange, but true. Oh well. good luck with your hunt for the culprit guys.