1997 Grand Am overheats in stop an go traffic but not when driving on freeway at 65-70mph

Check coolant level,could be air lock!

Replace your coolant temperature switch,it's screwed into block by oil filter.Here's a picture of what it look's like.Your water pump working properly.Are your spark plugs burning clean,not oily from bad piston rings?

Yeah,fan probably needs replacing,or u could change out to the double set of electric fans.Most kits are easy to install and not real bad on the wallet

if your vehicle has electric cooling fans it could be that they are not working,if this is the case when you are on the freeway you don't need the cooling fans you only need them when the vehicle is not moving as there is no air going through the radiator to keep the engine cool......hope this helps......cheers.

This may not be an actual problem, but rather it is likely normal. What is important is do the cooling fan(s) come on, and when they do, does that stop the heating up?
If fans work properly, are you making ENOUGH temperature? have you replaced the thermostat, lately? My thought is for generating enough heat, and not causing the overheating.....although the thermostat certainly can make overheat, I just doubt it in your case.

Try cleaning the throttle body and checking the air filter

This sounds like the electric cooling fans aren't turning on. Could be a bad coolant temp fan sensor, or the associated wiring to it

note if it overheats on the freeway or in city driving. If it overheats soon after you leave the house then in has to be the thermostat. If it overheats at city driving where there are lots of stop and go driving or while you are parked with the motor running, then check the radiator fan function properly. If it takes a while to overheat and tend to do it when driving on the freeway, it is a clogged/dirty radiator. If it looses coolant due to a leak, then it will also overheat. The least likely cause which don't even pertain to newer car is a retarted timing. A retarted timing causes a car to loose noticable loose of power accompanied by overheating. A retartded timing is usually common in older car where timing is adjustable by turning the distributor. Your car is exempt from this.

if it overheats at freeway speed, its a dirty radiator(flushing it usually don't help but you can try) If it overheats it traffic, then it is the automatic radiator fan(usually driven by electric motor). On some ocation an overheating is caused by retarded timing, but very unlikely on your vehicle since it is computerized.

freeway driving gets more air across the radiator
so the temp sender unit is faulty as this activates the fan by completing the fans circuit!
replace it & al should be A OK !!
Cheers Rob