2005 3.5SE (5spd.) Engine Trouble

[ZJenkins]

I started financing my 05 Altima in Feb. of 07, it had 32k on it. The day after singing the engine light comes on, I take it in, the code read Multiple Miss-fire etc. so they replaced all the fuel injectors. The light continues to come on and off regularly, it now has 53k and up to this point fuel lines have been replaced, 02 Sensors (all of them), ECU, and pretty much everything under the sun.

Last week the engine starts shaking violently at a stop, and the light is blinking, I turn it off and have it towed. The right Catalytic converter went and took out an EGR vavle in the process (I'm concerned that this may have cause more serius damage?), the parts were replaced by the factory/dealership, and the car seems to run at 100% again. Two days later and the light comes on for about 3-4 cycles and goes away, I have not yet took it in to get the code read.

Has anyone seen or have similar problems?