Check Engine light is on, how do I get the codes with out a reader? I put in a new EGR and then the idle went too low and the engine shuts off. I unplugged the battery after replacing the EGR and drove around for ~30 minutes to try and let it reset itself in "Normal" driving conditions to the new EGR. Still won't idle correctly (goes below 500 and shuts down).

I put the old EGR back in and no difference. I don't think I knocked anything else bad?