With the A/C on I get a voltage drop and a code 53(EGR control). I'm thinking if I have my alternator tested and if I have to replace it(seemed to be charging battery okay)I should see the code go away ?Checked battery for Voltage while running (14.6 v) EGR seemed to move easily(pushed up on the bottom for free movement) Anyone have any thoughts on what else to check? Car seems to run fine otherwise.