Pontiac Repair: engine missing? stalling?, vacuum leaks, warm thanks

Question
I have a 97 sunfire w/ 2.2L. A few months back it wouldn't start so we had a shop look at it and they replaced a fuel injector saying it was leaking into the cycl.  Ever since then the car has been rough on take off and shifting at low to medium RPM's. It is a standard trans. and makes us feel as though we have forgoten how to drive with a clutch at times.  The problem seems to be worse when the engine is warm. Thanks for any ideas.

Answer
Hi, what kind of rough take off is jumping or stall?
Sorry i did not see the engine missing and stall in the subject. Have you check the plugs and wires, check for a vacuum leaks at the injectors. a plug wire in the wrong place can cause this. it could be the injectors, when replacing injectors all of them should be replaced.