96 Monte

I have a 96 Monte with 140,000. It burns a little AF, about a pint every 10,000 miles and is extremely sluggish when the motor is warmed up. The check engine light comes on and goes off like crazy. If I had a dollar every time it went off I would have been able to put down money on a new car. Dealer says it is the #2 and 3 injector so they ran cleaner through and hit me for a $100. No fix. The resevoir for the AF is a little dirty with Oil but no AF in the oil. Sounds like the elusive Intake Gasket problem. Any other thoughts? Thanks. When the car is cold or newly started for the day it runs like a striped ass ape but when it gets warmed up and the moter expands I ahve problems. It feels like it is only running on three or four cylinders. Help.