Are you sure you're not getting a low exhaust gas temp code?
All the EGT sensor is used for is to throw a CEL (basically) so input from that is not going to cause any problems as far as how the car runs. However, if you are in fact getting a code for high exhaust gas temp then there is something else wrong. EGTs measured in the uppipe will be much lower without the catalytic converter in there. High EGTs is a sign of lean condition.