My check engine light and TCS light came on. Code

P0401: Isufficient Flow Detected in EGR system.
-clean the EGR port with the carburetor cleaner.
-clean the EGR passage inside the EGR valve with the caburetor cleaner.
Reset the light, if the light still coming back, then replace the EGR valve.

The code is for the EGR .that is the exhaust gas return.the egr valve is on the intake manifold on the rear drivers side.if you remove the egr,you will find that the intake port is full of carbon.clean it out with carb cleaner and a piece of wire 1/2 size of a coathanger.disconnect the battery and that will erase the check engine light. but you will need your radio code,unless you wire 12 volts to the radio fuse memory circuit.
once the car is driven thru a typical drive cycle,the monitors for 02 sensor,evap egr and catalyst will re set and unless the egr valve is defective,the check engine light will stay off.the egr operates at 2500 rpm and up,and symptoms include loss of power.make sure to drive the car on the highway once a week for 20 minutes to eliminate carbon build up.most mechanics that know what they are doing can fix the problem in an hour.The ones that do not will pull the intake manifold or replace the egr valve itself,which will not fix the problem.the carbon has to be removed from the egr port on the intake.it is not needed to pull the intake manifold.