When I let my car sit for awhile, it always runs a bit sluggish at first so I pressed the throttle a bit and my car turned on the engine light and then threw codes for misfires on cylinder 3. I just replaced the plugs and coils on this car about 8,000 miles ago so I don't believe that's the problem. The electronic fuel pump is around 10,000 miles ago and same with the fuel filter. I think its probably the fuel injector on cylinder 3. Is there a way to clean these or refurbish them or service them in anyway or do they have to be replaced. I'm not sure how you would really test them since they are basically just a switch and the fuel needs to be under pressure. I took a look at those bad boys are expensive $300 or so.