2000 Intrepid 2.7 Leaky injectors?

2000 Intrepid, 79k miles, engine light goes on for a while, then off for a while and gives 0172 and 0175 codes. Engine runs smoothly 95% of the time. When the car has been sitting for a while (6+ hours), but in hot weather, it may idle roughly for a minute or two. The mechanic suspects this is due to leaky or worn injectors and that the computer is trying to lean it up. He says the O2 sensors are within specs. Has anyone heard of leaky injector problems like this? Is there something else that I should look for or try first?

An earlier thread for a 95 with the same problem had a response from someone who recommended changing the intake manifold gaskets. Any relevance in this situation?

Try putting some fuel injector cleaner in the tank and see if it just may be a sticky or clogged injector causing the problem, it may cure it after you use up most of that tankful. Make sure the container says "Safe for Catalytic Converters" (Most all of them do) and follow the directions on how much gas to how much cleaner to put in the tank (Do not run it strong) and see what happens.