Grand Am Won't Accelerate

I have a 2000 Grand Am Se 3.4 V6. 140 000 km
When I'm at a stop and i take off, the car stutters and accelerates extremely slowly. When I'm on the highway going about 100km/h or so and I want to give it some gas to pass another car the RPM'S stay low and nothing happens unless I floor the gas and then I get the service light. When I read the codes, it gives me Cylinder 3 misfire. I tried putting some fuel injector cleaner but it didn't really help much. Anybody have any ideas ?
Thanks in advance

I have a 2000 Grand Am Se 3.4 V6. 140 000 km
When I'm at a stop and i take off, the car stutters and accelerates extremely slowly. When I'm on the highway going about 100km/h or so and I want to give it some gas to pass another car the RPM'S stay low and nothing happens unless I floor the gas and then I get the service light. When I read the codes, it gives me Cylinder 3 misfire. I tried putting some fuel injector cleaner but it didn't really help much. Anybody have any ideas ?
Thanks in advance

spark plug died is my guess :p

Yes I would change your plugs & wires first.

If you are still getting misfires then start looking at the injector wiring around the intake for wire breaks.

Might also want to get your fuel pressure tested, should be 41-47psi. It can be tested from the shradder valve on the pass.side of the engine on the rear fuel rail.

Also that code will need cleared after the repairs are made.
If not it'll keep on missing out. ;)

I'm going to check the spark plugs and wires and see if that helps.