2002 Buick Lesabre fixing my car

P0201 - Injector Circuit Malfunction - Cylinder 1

You don't "change" anything until testing proves it to be necessary. First of all, you didn't list any symptoms, observations, or clues, so I have no idea what kind of problem you're trying to repair. More importantly, diagnostic fault codes never say to replace parts or that they're bad. They only indicate the circuit or system that needs further diagnosis, or the unacceptable operating condition. When a part is referenced in a fault code, it is actually the cause of that code only about half of the time. First you have to rule out wiring and connector terminal problems.

If you can't find anything wrong with the wiring, swap the injectors between two cylinders, erase the fault code, then see if a new code sets for the cylinder you moved the suspect injector to. If it does, the injector is a good suspect.

That's kind of confusing. Are you saying the engine stalls at times? And if so, when idling at a stop sign or when driving? If the "Battery" light turns on right after the engine stalls, that is normal because the charging system has stopped keeping the battery charged. It can't do that when the generator isn't spinning. If the "Battery" light turns on first, then the engine stalls many minutes later, that is a totally different story, and one that I have a valid answer for.

One intermittent injector circuit will cause a rough-running engine with low power, but it usually won't cause the engine to stall completely. The fault code you're looking into may be taking you on a wild goose chase. If you're just having an intermittent rough-running problem, swap two injectors like I mentioned, and see what happens.