Your C280 has a problem with a deteriorating engine harness? Is this the wiring harness? If not, what is it?
Secondly, my mechanic did pull the codes and that is how I knew the exact reason for the check engine light being on. Anyway, he reset them for now, and didn't have time to look at it today, but I am taking it in Friday morning. Will looking at the actual values of the firing voltage give you a more accurate idea on what the problem with cylinder 2 is? You also said to look at the wiring by pulling back the insulation? Are you talking about on the plug wires?
Is it safe to run my car without causing damage to the catalyst until Friday? He reset the codes and they have not come back on yet, but I still have a rough idle every 15 or so seconds. Thanks for all the help, I really appreciate it.

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)