1993 Dakota 2WD-Auto V6 AC. OHIO--had E-check and nearly flunked--high NOX. EGR passages clean but valve was faulty-replaced. Passed E-check BUT still had very high NOX---better but way high compared to other vehicles. Further reading suggests that EGR on this engine works only during cruise and not at low or high idle or WOT. Current Ohio E-check dyno test is at 25MPH which is barely off idle on this truck. I'm wondering if I still have an EGR problem OR is the test condition (25MPH) too slow? (Auto trans is a hybrid overdrive which kicks in early and each gear (2d & 3d) is in overdrive mode after initial takeoff. Only other thought I have is to push the OD-OFF button to try to have the rpm's higher at 25MPH?). I don't want to pollute----so any thoughts on this?