i need help my 89 aerostar failed emissions because my nox was high. well they all suggested that i replace the egr well it dont have one so how do i go about lowering the nox

 

I would start with removing the EGR valve, clean all of the carbon aut of it. Then check to ensure that the valve moved up and down when applying vacuum to it. This can be done by holding the EGR valve in your hand and connecting a hose to it's vacuum port, put the hose in your mouth and suck on it. The valve should move freely. Also blow thru the EGR pipe that connects to the exhaust pipe and vacuum line for the EGR valve to ensure there is no blockage there also. A dead/dying catalytic converter can also cause high NOX.