tt chip doesnt use it and if the solenoid is unplugged it wont throw a code but if it is plugged in and defective the solenoid will trip the code and yes you will see it , your egr being sucked in the solenoid is defective , just unplug the elec connector to solenoid and remove the vac line source at the tee and plug or remove tee section of hose and replace with a longer hose from check valve to the hvac check at firewall) so you dont have a vac leak .... reset ecm to remove code and youll be fine
on a side note your check valve before the egr solenoid may also be defective whick is what possible caused the egr solenoid to fail as it was allowed to see boost ..so test it and replace if needed to protect the hvac system from boost
if you need to smog the car and use an emmission chip (like the TT emmision chip) you will need to replace the egr solenoid and have the egr functional
