I am needing some help. I have a 1997 E320 with right at 100000 miles on it. the only trouble I have had out of the car is a bad o2 sensor. recently I have noticed that it idles rougher and I am getting codes P0133 bank 1 o2 sensor 1 slow response, P0140 bank 1 o2 sensor 2 no activity , PO301 cylinder 1 misfire.I changed all the plugs also new plug wires, new coils and the other o2 sensor but i still have the codes coming back. could my cats be bad also my gas mileage is not as good as it once was. just wondered if anyone else has had this problem. any info will be greatly appreciated.