The 1996 3.1 says the same thing. EGR flow Insufficient.
This is something some one ask on a website but I have no idea where the sensor or little device is at
most likely you have an EGR port clogged with carbon build-up, common on these 3.1L and 3.4L engines. remove the throttle cable bracket and look down the PCV tube hold on top of the intake. also check the PCV operation and ensure its not sucking oil out of the valve cover. if it is, oil will fall on top of the EGR port. may be easier to remove throttle body to clean carbon build up.
Hope this helps a lil
This is what I found on google not quite sure what it really means ?
