Do a quick compression test and pull the plugs and read them - make sure you don\'t have a problem like a bent valve or similar.
As for injectors - you can stick an automotive stethscope on them and listen for the ticking sound. You can also use a long screwdriver - just be careful.
Also check the knock sensor - didn\'t mention the engine, but most are between the middle cylinders (#2 and #3 on 4 cylinders, #3 and #4 on inline sixes, one on each side for V6s).
Hopefully, didn\'t hydrolock the engine - pretty hard to do, but I\'ve seen it happen. Good Luck.