The spark plugs were changed last week and I don't know when the spark plug wires were change. The last owner said he changed them a few months before he sold the car but I haven't been able to take him at his word thus far. If he did change them I would guess they were cheap ones....Ill research that and update you on the quality of the replacement.
I have been using a steel brush to take the corrosion off before I delete the CEL code, usually runs for 30-50 miles before it comes back on. When it does come back on it flashes for a bit before it goes solid and then will flash again.