I've seen the A/C evaporator 90% plugged with debris on these cars. It is
not too hard of a job to clean. At least on a four cylinder. I haven't done
it on a six. You'll need to remove the insulated metal duct on the engine
side of the fire wall. To do this you'll need to remove the two bolts for
the steering rack on the passenger side and loosen the two bolts on the
driver side. Use a rope to pull the rack forward. This provides enough
clearance to get to all the fasteners and to get the duct out.