A couple of months back while driving the car, cylinder 3 died on me and I had to limp home on 3 cylinders. After swapping around coil packs, I determined the coil pack was a dud and replaced it.
Car was running fine since, until about a week ago when I noticed that when I planted the throttle in 2nd gear or higher the CEL would flash from about 4k rpm on. There was no noticeable lose in power, change in sound or any misfires and usually the light would go out as soon as I let off the accelerator. Reading the ECU with Torque gave a pending Cylinder 3 misfire. Having a spare new coil pack around, I swapped that in, but still got the code. The last 2 days the CEL would stay on solid after I left off, and finally last night there was a noticeable noise and loss in power when I floored it. The noise sounded almost like a stuttering noise as. Lifting off again resolved the issue, and driving the car around the city this morning was fine, although I never accelerated hard.
It's had a new diverter valve, PCV and breather valve recently enough and the plugs aren't even a year old as is the fuel filter. Also recently changed the cam follower. I'm leaning towards the fuel injector, but I don't really want to have to pull off the manifold to swap around the injectors for testing sake.
Any suggestions?