What exactly does this code mean? I've looked it up refers to the egr control valve which I believe is the cylinder on the pass side with vac lines running to it. This is 87 2.8. The car runs fine and I'm not getting any worse gas mileage still 300-310 out of a tank on 500,000 miles on the motor. Could there be a possibility that the vac lines are clogged since some hook up the the tb. I have my air baffles cut so my air filters tend to get fairly dirty.