2002 Mitsubishi Galant 2.4L 4cyl

My Mitsubishi Galant doesn't seem to be firing right. When I step on the gas the car is real sluggish getting going. The rpm's go up but the car doesn't accelerate like it should. I took it to get diagnosed because the service engine soon light came on. The mechanic said that the #2 cylinder wasn't firing right. He said to change the plugs. So, I did. It helped for about 2 days and then started doing it again. I checked the plugs when the engine was completely cooled so I wouldn't strip the aluminum block. The plugs were fine. I'm thinking that maybe the spark plug wires need to be replaced. I don't think it's the ignition coil packs because I know there's 2 of those. One on the #2 and one on the #4 cylinder and if one of those were faulty there would be two cylinders messing up and the rest of the cylinders are firing just fine. So should I try replacing the spark plug wires?