I tried to change plugs / wires once before using bosch platinum plugs but was unable to change the wires... it seemed too difficult. Car ran like crap after plug change (I did gap them correctly and torqued (sp) them correcly when installing. I ended up putting the old plugs back in and then everything was fine.
I'm almost thiking plugs too but am going by what the code says.
I am really wondering if the EGR system could cause the problems described? I want to stay away from the plugs until it gets warmer out.