Toyota Repair: Check Engine light, egr valve position, toyota technician

Question
Is this the reason why sometimes my engine wouldn't start?  Sometimes the engine stalls because of low rpm.  Toyota technician mentioned something about having a carbon built up.  So what he recommended in the meantime is to put the engine in high revolution for about 1 minute and let go, and this makes the car to be in idle. And your suggestion is to start replacing the EGR VSV and reset the code?

Thanks
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Followup To
Question -
I have a check engine light in my car and when I used a computer to run diagnostic,  it gave me two codes, P0402 and P1411.  When I called Autozone, they told me I have to replace EGR Valve.  BTW, my car is a Toyota Avalon 1998 with 140K.  Also, sometimes my car dies right after I started it. The idle goes really low until the engine dies.  Please advise.
Answer -
The PO402 code is "excessive egr gas flow detected"
The P1411 refers to the EGR valve position sensor.
The egr valve is expensive, so unless there was a specific test performed that proves that the egr valve is staying open I would not replace it because it is the least likely cause.
There is common cause for the PO402 code:
The EGR vacuum switching valve(VSV) is keeping the egr valve open when it is not supposed to,this will cause the rough idle and stalling, the position sensor does nothing other than tell the computer how far and when the egr valve is open or closed it doesn't control the valve, if the P1411 code was the only one I would recommend replacing the position sensor but since there is the 402 code I would recommend replacing the inexpensive EGR vsv first, it's located under the black engine cover, there are some other VSVs that are not related to the egr system so be sure you identify the correct one, call the toyota parts department they should be able to help.  

Answer
The stalling condition may be caused by a malfunctioning idle speed control valve, it is located on the throttle body and can be cleaned, at the same time while the trhottle body is off it should be cleaned also, this fixes the idle problem about 90% of the time.  Since the idle problem can also be caused by excessive EGR gas flow it should be adressed first.