im thinking clogged cat if new wires and cleaning the coils dont fix it. being you have 225,000 on it.
flashing cel usually comes back to being a clogged cat, or needing a tune up real bad.
you can pull the up stream o2 sensor to make a exhaust leak. yes it will sound like crap but if it feels like its getting more power now the cat is clogged up.
and never unplug a sensor while the car is running. car off unplug them, then fire it back up. this really only works for the maf to see if its not working well too.
