2004 c230 runs rich then lean

What is your question?

i have replaced spark plugs, fuel filter,maf, upstream oxygen sensor. still the light comes on 171, 172, 175. i put over 1600.00 in and no change any ideas

What makes this problem better or worse?

no change

How long has your 2004 Mercedes-Benz C230 had this problem?

2 months