Engine Codes

The EGR is run via engine vacuum, so you may have a break in the line. The plastic vacuum lines are easily broken; they get brittle as they age. Also, it's really easy to hook up the wrong vacuum hose to the EGR; make sure GREEN is on the EGR, and RED is on the intake manifold. If one or both of those vacuum hoses is black rubber, someone has replaced broken parts of the hose. Trace the hoses back until you get to the plastic and see the original color.

The other codes may mean nothing; you have to press the brake and the overdrive switch during the KOEO test, or you'll get those codes. If you have a higher-end code reader, they'll tell you when to press both. Otherwise, it's difficult to tell when it's time to hit them during KOEO.